* [PATCH v6 00/16] Synopsys DisplayPort Controller improvements for Rockchip platforms
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
This patch series updates the Synopsys Designware DisplayPort bridge
together with the only existing user: The Rockchip RK3576/RK3588:
1. Follow-up bridges (PHY, USB-C connector)
This is needed to get USB-C DP AltMode working; I've followed
the Qualcomm driver as reference
2. Runtime PM
The initial driver has been upstreamed without RPM; add it to
avoid wasting power when nothing is plugged
3. Audio
The initial driver has been upstreamed without audio support;
this adds all missing bits for audio with single stream transport
To properly make use of the bridge code the following USBDP PHY series
is also needed:
https://lore.kernel.org/all/20260714-rockchip-usbdp-cleanup-v13-0-6cb3e769d4c5@collabora.com/
This series can be applied without the USBDP side. In that case USB-C
support won't work as the mainline USBDP side does not register as a
DRM bridge. As upstream DT binding for USBDP does not yet support
proper ports, no such board should be upstream.
Boards using the DP controller for native DP connectors (or HDMI
bridges), currently directly link to the connector/hdmi bridge. These
are not affected by the USBDP changes and should keep working in any
case. The difference is, that this series the DRM side is aware of the
link. I don't have any of those boards, so this code path is untested.
I added a dedicated bridge callback for out-of-band hotplug events,
which is separate from the hotplug_notify. I have a feeling, that
there might be a better solution, but haven't found it. Please comment.
Changes in v6:
- Link to v5: https://lore.kernel.org/r/20260724-synopsys-dw-dp-improvements-v5-0-9445c2e87441@collabora.com
- Fix overlong commit message in mutex patch
- Update MEDIA_BUS_FMT_FIXED patch, to use input format as output format
when output format is MEDIA_BUS_FMT_FIXED (Sashiko)
- Drop patch moving dw_dp_bridge_atomic_get_output_bus_fmts (no longer
needed)
- Reword the comment about platforms other than RK3576 and RK3588
shouldn't get the VO GRF from the USBDP to make it more obvious
that no such platform exist at the moment and thus the alternative
path will not be implemented at this point in time (Sashiko)
- Update the runtime PM code to have much better error handling
as well as support for platforms not using runtime PM (Sashiko)
- Update the runtime PM code to keep the device suspended when
probed, but unbound as a nice side effect
- Fix error handling for dw_dp_audio_infoframe_send() in audio
patch (Sashiko)
- Fix typo in sample width check in audio patch (Sashiko)
- Improve cleanup of SDP in audio patch (Sashiko)
Changes in v5:
- Link to v4: https://lore.kernel.org/r/20260721-synopsys-dw-dp-improvements-v4-0-f0f4a4ede712@collabora.com
- Add new patch to cancel pending HPD work on unbind (Sashiko)
- Add new patch to add missing mutex cleanups on module removal (Sashiko)
- Add new patch moving dw_dp_bridge_atomic_get_output_bus_fmts
- Update MEDIA_BUS_FMT_FIXED patch to avoid fixed RGB888 format
and instead use whatever works for the negotiated bandwidth (Sashiko)
- Add more error checking for runtime PM patches (Sashiko)
- Ensure runtime PM is held in interrupt handler (Sashiko)
- Fix usbc_mode logic inversion for runtime PM in unbind (Sashiko)
- Move sleep for HPD_HOT_PLUG from hotplug handler to runtime
resume function; no need to sleep when runtime PM is kept
active and runtime PM resume is a slow operation anyways. (Sashiko)
- Add new patch to protect sdp_reg_bank from concurrent access (Sashiko)
- Add new patch to use regmap_set_bits in dw_dp_send_sdp()
- Update DT binding patch to be all about the selected solution and
mention the ABI break
- Clear SDP in the audio patch on unprepare (Sashiko)
- Add a comment, that only 1,2 or 8 channels are supported (Sashiko)
- Error out on unsupported sample_width (Sashiko)
- Fix missing error check for clock enable (Sashiko)
Changes in PATCHv4:
- Link to v3: https://lore.kernel.org/all/20260612-synopsys-dw-dp-improvements-v3-0-dc61e6352508@collabora.com/
- Drop "Simplify driver data setting" (effectively reverted later on)
- Add "Fix incorrect resource lifetimes in bind callback", which
affects all following patches quite a bit (Sashiko)
- Update "Add follow-up bridge support" to mention that fatal errors
are fine (Sashiko)
- Update "Add out-of-band HPD notify handler" to use
drm_for_each_bridge_in_chain() instead of
drm_for_each_bridge_in_chain_scoped() required after rebase to
latest drm-misc-next
- Add 100ms sleep in hpd detect functions after runtime resume in the
"Add Runtime PM support" patch (Andy Yan)
- Keep runtime PM enabled if DP is used without USB-C to avoid missing
HPD signals in "Add Runtime PM support" patch (Andy Yan)
- Update patch description of DT binding patch and drop RFC tag
- Use pm_runtime_resume_and_get() in the audio startup function, which
allows easy error handling (Sashiko)
- Avoid updating audio_interface in the audio prepare function when
an error related early exit happens (Sashiko)
- Add error handling for clock prepare calls in audio prepare function
(Sashiko)
Changes in PATCHv3:
- Link to v2: https://lore.kernel.org/r/20260501-synopsys-dw-dp-improvements-v2-0-d7e7f6bac77f@collabora.com
- Collect Reviewed-by on "Simplify driver data setting" patch (Andy Yan)
- Use of_drm_get_bridge_by_endpoint instead of devm_drm_of_get_bridge (Luca Ceresoli)
- Use FIELD_PREP_WM16 instead of FIELD_PREP_WM16_CONST (Chaoyi Chen)
- Rebase to latest drm-misc-next (Dropped Cristian's patches)
Changes in PATCHv2:
* Link to v1: https://lore.kernel.org/r/20260326-synopsys-dw-dp-improvements-v1-0-501849162290@collabora.com
* rebased to latest drm-misc-next
* prepended the Patches from Cristian's cleanup series, as they also
needed a rebase and should be merged first
https://lore.kernel.org/dri-devel/20260327-drm-rk-fixes-v3-0-fd2e6900c08c@collabora.com/
* fix issue with the audio stream (un)prepare handling in last patch
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
Sebastian Reichel (16):
drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
drm/bridge: synopsys: dw-dp: Cancel pending HPD work on unbind
drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal
drm/bridge: synopsys: dw-dp: Add missing reinit_completion
drm/bridge: synopsys: dw-dp: Free output_fmts when none are valid
drm/bridge: synopsys: dw-dp: Support MEDIA_BUS_FMT_FIXED
drm/bridge: synopsys: dw-dp: Add follow-up bridge support
drm/bridge: Add out-of-band HPD notify handler
drm/bridge: synopsys: dw-dp: Support software triggered OOB HPD
drm/rockchip: dw_dp: Implement out-of-band HPD handling
drm/bridge: synopsys: dw-dp: Add Runtime PM support
drm/rockchip: dw_dp: Add runtime PM support
drm/bridge: synopsys: dw-dp: Protect sdp_reg_bank from concurrent access
drm/bridge: synopsys: dw-dp: Use regmap_set_bits in dw_dp_send_sdp
dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells
drm/bridge: synopsys: dw-dp: Add audio support
.../bindings/display/rockchip/rockchip,dw-dp.yaml | 9 +-
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 607 ++++++++++++++++++---
drivers/gpu/drm/display/drm_bridge_connector.c | 6 +
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 219 +++++++-
include/drm/bridge/dw_dp.h | 11 +-
include/drm/drm_bridge.h | 14 +
6 files changed, 762 insertions(+), 104 deletions(-)
---
base-commit: c182a2ae13886463f7ae36e034449477306d182b
change-id: 20260325-synopsys-dw-dp-improvements-7da2e98df1dd
Best regards,
--
Sebastian Reichel <sebastian.reichel@collabora.com>
^ permalink raw reply [flat|nested] 41+ messages in thread* [PATCH v6 01/16] drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
Sashiko, kernel, linux-arm-kernel
Currently the Synopsys DesignWare DP controller driver's bind function
requests lots of resources using device managed functions. These are
free'd on driver removal instead of at unbind time. Fix this discrepancy
by introducing a new probe helper function and moving over most of the
early resource acquisitions.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 128 +++++++++++++++---------------
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 53 ++++++++-----
include/drm/bridge/dw_dp.h | 5 +-
3 files changed, 99 insertions(+), 87 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 3445c82e6f50..368e1f85e625 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1954,20 +1954,72 @@ static const struct regmap_config dw_dp_regmap_config = {
.rd_table = &dw_dp_readable_table,
};
-static void dw_dp_phy_exit(void *data)
+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
{
- struct dw_dp *dp = data;
+ struct device *dev = dp->dev;
+ struct drm_bridge *bridge;
+ int ret;
+
+ bridge = &dp->bridge;
+ bridge->of_node = dev->of_node;
+ bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+ bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
+ bridge->ycbcr_420_allowed = true;
+
+ drm_bridge_add(bridge);
+
+ dp->aux.dev = dev;
+ dp->aux.drm_dev = encoder->dev;
+ dp->aux.name = dev_name(dev);
+ dp->aux.transfer = dw_dp_aux_transfer;
+ ret = drm_dp_aux_register(&dp->aux);
+ if (ret) {
+ dev_err_probe(dev, ret, "Aux register failed\n");
+ goto unregister_bridge;
+ }
+
+ ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to attach bridge\n");
+ goto unregister_aux;
+ }
+
+ dw_dp_init_hw(dp);
+ ret = phy_init(dp->phy);
+ if (ret) {
+ dev_err_probe(dev, ret, "phy init failed\n");
+ goto unregister_aux;
+ }
+
+ enable_irq(dp->irq);
+
+ return 0;
+
+unregister_aux:
+ drm_dp_aux_unregister(&dp->aux);
+
+unregister_bridge:
+ drm_bridge_remove(bridge);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dw_dp_bind);
+
+void dw_dp_unbind(struct dw_dp *dp)
+{
+ disable_irq(dp->irq);
phy_exit(dp->phy);
+ drm_dp_aux_unregister(&dp->aux);
+ drm_bridge_remove(&dp->bridge);
}
+EXPORT_SYMBOL_GPL(dw_dp_unbind);
-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
- const struct dw_dp_plat_data *plat_data)
+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct dw_dp *dp;
- struct drm_bridge *bridge;
+ struct device *dev = &pdev->dev;
void __iomem *res;
+ struct dw_dp *dp;
int ret;
dp = devm_drm_bridge_alloc(dev, struct dw_dp, bridge, &dw_dp_bridge_funcs);
@@ -1976,9 +2028,8 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
dp->dev = dev;
dp->pixel_mode = plat_data->pixel_mode;
-
dp->plat_data.max_link_rate = plat_data->max_link_rate;
- bridge = &dp->bridge;
+
mutex_init(&dp->irq_lock);
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
init_completion(&dp->complete);
@@ -2035,69 +2086,20 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
return ERR_CAST(dp->rstc);
}
- bridge->of_node = dev->of_node;
- bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
- bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
- bridge->ycbcr_420_allowed = true;
-
- ret = devm_drm_bridge_add(dev, bridge);
- if (ret)
- return ERR_PTR(ret);
-
- dp->aux.dev = dev;
- dp->aux.drm_dev = encoder->dev;
- dp->aux.name = dev_name(dev);
- dp->aux.transfer = dw_dp_aux_transfer;
- ret = drm_dp_aux_register(&dp->aux);
- if (ret) {
- dev_err_probe(dev, ret, "Aux register failed\n");
- return ERR_PTR(ret);
- }
-
- ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
- if (ret) {
- dev_err_probe(dev, ret, "Failed to attach bridge\n");
- goto unregister_aux;
- }
-
- dw_dp_init_hw(dp);
-
- ret = phy_init(dp->phy);
- if (ret) {
- dev_err_probe(dev, ret, "phy init failed\n");
- goto unregister_aux;
- }
-
- ret = devm_add_action_or_reset(dev, dw_dp_phy_exit, dp);
- if (ret)
- goto unregister_aux;
-
dp->irq = platform_get_irq(pdev, 0);
- if (dp->irq < 0) {
- ret = dp->irq;
- goto unregister_aux;
- }
+ if (dp->irq < 0)
+ return ERR_PTR(dp->irq);
ret = devm_request_threaded_irq(dev, dp->irq, NULL, dw_dp_irq,
- IRQF_ONESHOT, dev_name(dev), dp);
+ IRQF_ONESHOT | IRQF_NO_AUTOEN, dev_name(dev), dp);
if (ret) {
dev_err_probe(dev, ret, "failed to request irq\n");
- goto unregister_aux;
+ return ERR_PTR(ret);
}
return dp;
-
-unregister_aux:
- drm_dp_aux_unregister(&dp->aux);
- return ERR_PTR(ret);
}
-EXPORT_SYMBOL_GPL(dw_dp_bind);
-
-void dw_dp_unbind(struct dw_dp *dp)
-{
- drm_dp_aux_unregister(&dp->aux);
-}
-EXPORT_SYMBOL_GPL(dw_dp_unbind);
+EXPORT_SYMBOL_GPL(dw_dp_probe);
MODULE_AUTHOR("Andy Yan <andyshrk@163.com>");
MODULE_DESCRIPTION("DW DP Core Library");
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index b23efb153c9e..005938dc66c9 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -26,7 +26,7 @@
struct rockchip_dw_dp {
struct dw_dp *base;
struct device *dev;
- struct rockchip_encoder encoder;
+ struct rockchip_encoder *encoder;
};
static int dw_dp_encoder_atomic_check(struct drm_encoder *encoder,
@@ -73,37 +73,28 @@ static const struct drm_encoder_helper_funcs dw_dp_encoder_helper_funcs = {
static int dw_dp_rockchip_bind(struct device *dev, struct device *master, void *data)
{
- struct platform_device *pdev = to_platform_device(dev);
- const struct dw_dp_plat_data *plat_data;
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
struct drm_device *drm_dev = data;
- struct rockchip_dw_dp *dp;
struct drm_encoder *encoder;
struct drm_connector *connector;
int ret;
- dp = drmm_kzalloc(drm_dev, sizeof(*dp), GFP_KERNEL);
- if (!dp)
+ dp->encoder = drmm_kzalloc(drm_dev, sizeof(*dp->encoder), GFP_KERNEL);
+ if (!dp->encoder)
return -ENOMEM;
- dp->dev = dev;
- platform_set_drvdata(pdev, dp);
-
- plat_data = of_device_get_match_data(dev);
- if (!plat_data)
- return -ENODEV;
-
- encoder = &dp->encoder.encoder;
+ encoder = &dp->encoder->encoder;
encoder->possible_crtcs = drm_of_find_possible_crtcs(drm_dev, dev->of_node);
- rockchip_drm_encoder_set_crtc_endpoint_id(&dp->encoder, dev->of_node, 0, 0);
+ rockchip_drm_encoder_set_crtc_endpoint_id(dp->encoder, dev->of_node, 0, 0);
ret = drmm_encoder_init(drm_dev, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
if (ret)
return ret;
drm_encoder_helper_add(encoder, &dw_dp_encoder_helper_funcs);
- dp->base = dw_dp_bind(dev, encoder, plat_data);
- if (IS_ERR(dp->base))
- return PTR_ERR(dp->base);
+ ret = dw_dp_bind(dp->base, encoder);
+ if (ret)
+ return ret;
connector = drm_bridge_connector_init(drm_dev, encoder);
if (IS_ERR(connector)) {
@@ -128,12 +119,30 @@ static const struct component_ops dw_dp_rockchip_component_ops = {
.unbind = dw_dp_rockchip_unbind,
};
-static int dw_dp_probe(struct platform_device *pdev)
+static int dw_dp_rockchip_probe(struct platform_device *pdev)
{
+ const struct dw_dp_plat_data *plat_data;
+ struct device *dev = &pdev->dev;
+ struct rockchip_dw_dp *dp;
+
+ plat_data = of_device_get_match_data(dev);
+ if (!plat_data)
+ return -ENODEV;
+
+ dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
+ if (!dp)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, dp);
+ dp->dev = dev;
+
+ dp->base = dw_dp_probe(pdev, plat_data);
+ if (IS_ERR(dp->base))
+ return PTR_ERR(dp->base);
+
return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
}
-static void dw_dp_remove(struct platform_device *pdev)
+static void dw_dp_rockchip_remove(struct platform_device *pdev)
{
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
@@ -161,8 +170,8 @@ static const struct of_device_id dw_dp_of_match[] = {
MODULE_DEVICE_TABLE(of, dw_dp_of_match);
struct platform_driver dw_dp_driver = {
- .probe = dw_dp_probe,
- .remove = dw_dp_remove,
+ .probe = dw_dp_rockchip_probe,
+ .remove = dw_dp_rockchip_remove,
.driver = {
.name = "dw-dp",
.of_match_table = dw_dp_of_match,
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index 22105c3e8e4d..a82412a9e769 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -22,7 +22,8 @@ struct dw_dp_plat_data {
u8 pixel_mode;
};
-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
- const struct dw_dp_plat_data *plat_data);
+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
void dw_dp_unbind(struct dw_dp *dp);
+
+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data);
#endif /* __DW_DP__ */
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 01/16] drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
Currently the Synopsys DesignWare DP controller driver's bind function
requests lots of resources using device managed functions. These are
free'd on driver removal instead of at unbind time. Fix this discrepancy
by introducing a new probe helper function and moving over most of the
early resource acquisitions.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 128 +++++++++++++++---------------
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 53 ++++++++-----
include/drm/bridge/dw_dp.h | 5 +-
3 files changed, 99 insertions(+), 87 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 3445c82e6f50..368e1f85e625 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1954,20 +1954,72 @@ static const struct regmap_config dw_dp_regmap_config = {
.rd_table = &dw_dp_readable_table,
};
-static void dw_dp_phy_exit(void *data)
+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
{
- struct dw_dp *dp = data;
+ struct device *dev = dp->dev;
+ struct drm_bridge *bridge;
+ int ret;
+
+ bridge = &dp->bridge;
+ bridge->of_node = dev->of_node;
+ bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+ bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
+ bridge->ycbcr_420_allowed = true;
+
+ drm_bridge_add(bridge);
+
+ dp->aux.dev = dev;
+ dp->aux.drm_dev = encoder->dev;
+ dp->aux.name = dev_name(dev);
+ dp->aux.transfer = dw_dp_aux_transfer;
+ ret = drm_dp_aux_register(&dp->aux);
+ if (ret) {
+ dev_err_probe(dev, ret, "Aux register failed\n");
+ goto unregister_bridge;
+ }
+
+ ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to attach bridge\n");
+ goto unregister_aux;
+ }
+
+ dw_dp_init_hw(dp);
+ ret = phy_init(dp->phy);
+ if (ret) {
+ dev_err_probe(dev, ret, "phy init failed\n");
+ goto unregister_aux;
+ }
+
+ enable_irq(dp->irq);
+
+ return 0;
+
+unregister_aux:
+ drm_dp_aux_unregister(&dp->aux);
+
+unregister_bridge:
+ drm_bridge_remove(bridge);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dw_dp_bind);
+
+void dw_dp_unbind(struct dw_dp *dp)
+{
+ disable_irq(dp->irq);
phy_exit(dp->phy);
+ drm_dp_aux_unregister(&dp->aux);
+ drm_bridge_remove(&dp->bridge);
}
+EXPORT_SYMBOL_GPL(dw_dp_unbind);
-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
- const struct dw_dp_plat_data *plat_data)
+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct dw_dp *dp;
- struct drm_bridge *bridge;
+ struct device *dev = &pdev->dev;
void __iomem *res;
+ struct dw_dp *dp;
int ret;
dp = devm_drm_bridge_alloc(dev, struct dw_dp, bridge, &dw_dp_bridge_funcs);
@@ -1976,9 +2028,8 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
dp->dev = dev;
dp->pixel_mode = plat_data->pixel_mode;
-
dp->plat_data.max_link_rate = plat_data->max_link_rate;
- bridge = &dp->bridge;
+
mutex_init(&dp->irq_lock);
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
init_completion(&dp->complete);
@@ -2035,69 +2086,20 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
return ERR_CAST(dp->rstc);
}
- bridge->of_node = dev->of_node;
- bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
- bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
- bridge->ycbcr_420_allowed = true;
-
- ret = devm_drm_bridge_add(dev, bridge);
- if (ret)
- return ERR_PTR(ret);
-
- dp->aux.dev = dev;
- dp->aux.drm_dev = encoder->dev;
- dp->aux.name = dev_name(dev);
- dp->aux.transfer = dw_dp_aux_transfer;
- ret = drm_dp_aux_register(&dp->aux);
- if (ret) {
- dev_err_probe(dev, ret, "Aux register failed\n");
- return ERR_PTR(ret);
- }
-
- ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
- if (ret) {
- dev_err_probe(dev, ret, "Failed to attach bridge\n");
- goto unregister_aux;
- }
-
- dw_dp_init_hw(dp);
-
- ret = phy_init(dp->phy);
- if (ret) {
- dev_err_probe(dev, ret, "phy init failed\n");
- goto unregister_aux;
- }
-
- ret = devm_add_action_or_reset(dev, dw_dp_phy_exit, dp);
- if (ret)
- goto unregister_aux;
-
dp->irq = platform_get_irq(pdev, 0);
- if (dp->irq < 0) {
- ret = dp->irq;
- goto unregister_aux;
- }
+ if (dp->irq < 0)
+ return ERR_PTR(dp->irq);
ret = devm_request_threaded_irq(dev, dp->irq, NULL, dw_dp_irq,
- IRQF_ONESHOT, dev_name(dev), dp);
+ IRQF_ONESHOT | IRQF_NO_AUTOEN, dev_name(dev), dp);
if (ret) {
dev_err_probe(dev, ret, "failed to request irq\n");
- goto unregister_aux;
+ return ERR_PTR(ret);
}
return dp;
-
-unregister_aux:
- drm_dp_aux_unregister(&dp->aux);
- return ERR_PTR(ret);
}
-EXPORT_SYMBOL_GPL(dw_dp_bind);
-
-void dw_dp_unbind(struct dw_dp *dp)
-{
- drm_dp_aux_unregister(&dp->aux);
-}
-EXPORT_SYMBOL_GPL(dw_dp_unbind);
+EXPORT_SYMBOL_GPL(dw_dp_probe);
MODULE_AUTHOR("Andy Yan <andyshrk@163.com>");
MODULE_DESCRIPTION("DW DP Core Library");
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index b23efb153c9e..005938dc66c9 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -26,7 +26,7 @@
struct rockchip_dw_dp {
struct dw_dp *base;
struct device *dev;
- struct rockchip_encoder encoder;
+ struct rockchip_encoder *encoder;
};
static int dw_dp_encoder_atomic_check(struct drm_encoder *encoder,
@@ -73,37 +73,28 @@ static const struct drm_encoder_helper_funcs dw_dp_encoder_helper_funcs = {
static int dw_dp_rockchip_bind(struct device *dev, struct device *master, void *data)
{
- struct platform_device *pdev = to_platform_device(dev);
- const struct dw_dp_plat_data *plat_data;
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
struct drm_device *drm_dev = data;
- struct rockchip_dw_dp *dp;
struct drm_encoder *encoder;
struct drm_connector *connector;
int ret;
- dp = drmm_kzalloc(drm_dev, sizeof(*dp), GFP_KERNEL);
- if (!dp)
+ dp->encoder = drmm_kzalloc(drm_dev, sizeof(*dp->encoder), GFP_KERNEL);
+ if (!dp->encoder)
return -ENOMEM;
- dp->dev = dev;
- platform_set_drvdata(pdev, dp);
-
- plat_data = of_device_get_match_data(dev);
- if (!plat_data)
- return -ENODEV;
-
- encoder = &dp->encoder.encoder;
+ encoder = &dp->encoder->encoder;
encoder->possible_crtcs = drm_of_find_possible_crtcs(drm_dev, dev->of_node);
- rockchip_drm_encoder_set_crtc_endpoint_id(&dp->encoder, dev->of_node, 0, 0);
+ rockchip_drm_encoder_set_crtc_endpoint_id(dp->encoder, dev->of_node, 0, 0);
ret = drmm_encoder_init(drm_dev, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
if (ret)
return ret;
drm_encoder_helper_add(encoder, &dw_dp_encoder_helper_funcs);
- dp->base = dw_dp_bind(dev, encoder, plat_data);
- if (IS_ERR(dp->base))
- return PTR_ERR(dp->base);
+ ret = dw_dp_bind(dp->base, encoder);
+ if (ret)
+ return ret;
connector = drm_bridge_connector_init(drm_dev, encoder);
if (IS_ERR(connector)) {
@@ -128,12 +119,30 @@ static const struct component_ops dw_dp_rockchip_component_ops = {
.unbind = dw_dp_rockchip_unbind,
};
-static int dw_dp_probe(struct platform_device *pdev)
+static int dw_dp_rockchip_probe(struct platform_device *pdev)
{
+ const struct dw_dp_plat_data *plat_data;
+ struct device *dev = &pdev->dev;
+ struct rockchip_dw_dp *dp;
+
+ plat_data = of_device_get_match_data(dev);
+ if (!plat_data)
+ return -ENODEV;
+
+ dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
+ if (!dp)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, dp);
+ dp->dev = dev;
+
+ dp->base = dw_dp_probe(pdev, plat_data);
+ if (IS_ERR(dp->base))
+ return PTR_ERR(dp->base);
+
return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
}
-static void dw_dp_remove(struct platform_device *pdev)
+static void dw_dp_rockchip_remove(struct platform_device *pdev)
{
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
@@ -161,8 +170,8 @@ static const struct of_device_id dw_dp_of_match[] = {
MODULE_DEVICE_TABLE(of, dw_dp_of_match);
struct platform_driver dw_dp_driver = {
- .probe = dw_dp_probe,
- .remove = dw_dp_remove,
+ .probe = dw_dp_rockchip_probe,
+ .remove = dw_dp_rockchip_remove,
.driver = {
.name = "dw-dp",
.of_match_table = dw_dp_of_match,
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index 22105c3e8e4d..a82412a9e769 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -22,7 +22,8 @@ struct dw_dp_plat_data {
u8 pixel_mode;
};
-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
- const struct dw_dp_plat_data *plat_data);
+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
void dw_dp_unbind(struct dw_dp *dp);
+
+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data);
#endif /* __DW_DP__ */
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 01/16] drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:18 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:18 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: conor+dt, dri-devel, devicetree, robh
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
New issues:
- [High] Reusing the `drm_bridge` object across component bind/unbind cycles causes subsequent binds to permanently fail with `-EBUSY`.
Pre-existing issues:
- [High] Missing cancellation of `hpd_work` in the unbind path leads to a Use-After-Free.
--
--- Patch [1]: [PATCH v6 01/16] drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback ---
commit 7f5878cc180f32e03ed02693838ae580e5707a02
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/bridge: synopsys: dw-dp: Fix incorrect resource lifetimes in bind callback
This commit moves resource allocations to a new probe helper function to fix
resource lifetimes on driver removal. It updates the rockchip driver to use
the new probe and bind split.
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> index 3445c82e6f50e..368e1f85e6253 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
[ ... ]
> +int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
> {
[ ... ]
> + ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> + if (ret) {
> + dev_err_probe(dev, ret, "Failed to attach bridge\n");
> + goto unregister_aux;
> + }
[ ... ]
> +void dw_dp_unbind(struct dw_dp *dp)
> +{
> + disable_irq(dp->irq);
[Severity: High]
This is a pre-existing issue, but missing a work cancellation here can lead
to a use-after-free.
While disable_irq() waits for currently executing IRQ handlers to finish,
it does not cancel work items that have already been scheduled. If the IRQ
handler schedules dp->hpd_work right before disable_irq() runs, the work
remains queued.
If the component unbind is followed by a driver removal, devm will free the
struct dw_dp memory. Won't the asynchronously executing dw_dp_hpd_work() then
access freed memory? Could a cancel_work_sync(&dp->hpd_work) be added to
safely flush pending work?
> phy_exit(dp->phy);
> + drm_dp_aux_unregister(&dp->aux);
> + drm_bridge_remove(&dp->bridge);
[Severity: High]
Because the bridge allocation (embedded in struct dw_dp) was moved to
dw_dp_probe(), the same bridge object is now reused across component
bind/unbind cycles.
When drm_bridge_attach() is called during bind, it successfully links the
bridge and sets bridge->dev. However, drm_bridge_remove() in this unbind
path does not clear this pointer.
Doesn't this mean a subsequent bind attempt will permanently fail with -EBUSY
when drm_bridge_attach() sees that bridge->dev is already populated from the
previous bind?
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=1
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 02/16] drm/bridge: synopsys: dw-dp: Cancel pending HPD work on unbind
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
Sashiko, kernel, linux-arm-kernel
There is a race condition during device unbind: If the HPD interrupt
started an HPD worker exactly when the unbind happens, the worker
thread might access invalid resources. Avoid this by stopping any
pending work immediately after disabling the interrupt.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 368e1f85e625..21bd08571dcf 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -2009,6 +2009,7 @@ EXPORT_SYMBOL_GPL(dw_dp_bind);
void dw_dp_unbind(struct dw_dp *dp)
{
disable_irq(dp->irq);
+ cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 02/16] drm/bridge: synopsys: dw-dp: Cancel pending HPD work on unbind
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
There is a race condition during device unbind: If the HPD interrupt
started an HPD worker exactly when the unbind happens, the worker
thread might access invalid resources. Avoid this by stopping any
pending work immediately after disabling the interrupt.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 368e1f85e625..21bd08571dcf 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -2009,6 +2009,7 @@ EXPORT_SYMBOL_GPL(dw_dp_bind);
void dw_dp_unbind(struct dw_dp *dp)
{
disable_irq(dp->irq);
+ cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 03/16] drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
Sashiko, kernel, linux-arm-kernel
The driver is currently missing to fully clean up after itself. Ensure
that the mutex is cleaned up.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 21bd08571dcf..b28040d69fab 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -2031,10 +2031,13 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
dp->pixel_mode = plat_data->pixel_mode;
dp->plat_data.max_link_rate = plat_data->max_link_rate;
- mutex_init(&dp->irq_lock);
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
init_completion(&dp->complete);
+ ret = devm_mutex_init(dev, &dp->irq_lock);
+ if (ret)
+ return ERR_PTR(ret);
+
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res))
return ERR_CAST(res);
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 03/16] drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
The driver is currently missing to fully clean up after itself. Ensure
that the mutex is cleaned up.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 21bd08571dcf..b28040d69fab 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -2031,10 +2031,13 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
dp->pixel_mode = plat_data->pixel_mode;
dp->plat_data.max_link_rate = plat_data->max_link_rate;
- mutex_init(&dp->irq_lock);
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
init_completion(&dp->complete);
+ ret = devm_mutex_init(dev, &dp->irq_lock);
+ if (ret)
+ return ERR_PTR(ret);
+
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res))
return ERR_CAST(res);
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 03/16] drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:15 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:15 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: devicetree, conor+dt, robh, dri-devel
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
Pre-existing issues:
- [High] Missing reinit_completion() before AUX transfer causes subsequent transfers to falsely succeed if a timeout previously occurred or stray interrupts arrived.
- [High] Short HPD and Long HPD events share a single boolean state variable, causing critical hot plug events to be lost if interrupts arrive in quick succession.
- [High] Hardware is powered down and interrupts are disabled before the DP AUX interface is unregistered, allowing userspace to crash the system or hang by accessing powered-down hardware.
--
--- Patch [3]: [PATCH v6 03/16] drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal ---
commit 4a4bd90d7d64ae717e418a4501d8f02733f02d38
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/bridge: synopsys: dw-dp: Add missing mutex cleanups on module removal
The driver is currently missing to fully clean up after itself. Ensure
that the mutex is cleaned up.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> index 21bd08571dcfe..b28040d69fabf 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
[ ... ]
This is a pre-existing issue, but I noticed a potential problem in
dw_dp_aux_transfer():
value |= FIELD_PREP(AUX_ADDR, msg->address);
regmap_write(dp->regmap, DW_DP_AUX_CMD, value);
status = wait_for_completion_timeout(&dp->complete, timeout);
if (!status) {
[Severity: High]
Does this completion need to be reinitialized before the transfer?
If a previous transfer timed out and the hardware later replies,
could a subsequent transfer falsely succeed immediately because the
completion counter was left > 0?
[ ... ]
This isn't a bug introduced by this patch, but there is a potential
event loss in the HPD handler.
If a physical hotplug triggers an interrupt:
dw_dp_handle_hpd_event()
if (value & HPD_HOT_PLUG) {
dp->hotplug.long_hpd = true;
}
Could a subsequent short HPD interrupt (e.g., from a link status change)
overwrite this state before dw_dp_hpd_work() evaluates it?
dw_dp_handle_hpd_event()
if (value & HPD_IRQ) {
dp->hotplug.long_hpd = false;
[Severity: High]
If dw_dp_hpd_work() runs after this short pulse, will it read long_hpd as
false and perform a link retrain instead of notifying userspace of the
hotplug?
[ ... ]
This is also a pre-existing issue, but I noticed a potential hardware hang
in the unbind sequence just above the probe function:
void dw_dp_unbind(struct dw_dp *dp)
{
disable_irq(dp->irq);
cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
drm_dp_aux_unregister(&dp->aux);
[Severity: High]
Does this order allow userspace to access unpowered hardware?
Since phy_exit() powers down the PHY before the AUX interface is
unregistered, could a concurrent read/write to the /dev/drm_dp_auxN
character device cause a synchronous external abort or hardware hang?
> @@ -2031,10 +2031,13 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
> dp->pixel_mode = plat_data->pixel_mode;
> dp->plat_data.max_link_rate = plat_data->max_link_rate;
>
> - mutex_init(&dp->irq_lock);
> INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
> init_completion(&dp->complete);
>
> + ret = devm_mutex_init(dev, &dp->irq_lock);
> + if (ret)
> + return ERR_PTR(ret);
> +
> res = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(res))
> return ERR_CAST(res);
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=3
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 04/16] drm/bridge: synopsys: dw-dp: Add missing reinit_completion
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
Sashiko, kernel, linux-arm-kernel
The DP AUX transfer method uses a completion triggered by an interrupt,
which can timeout. If the function runs into the timeout and the
interrupt fires afterwards, the following DP aux transfer completion
would trigger immediately without waiting for the interrupt. This in
turn means the next one would also be broken and so on.
Fix this potential issue by re-initializing the completion before
sending the AUX command.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index b28040d69fab..2f0ee7ab7feb 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1465,6 +1465,8 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
if (WARN_ON(msg->size > 16))
return -E2BIG;
+ reinit_completion(&dp->complete);
+
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 04/16] drm/bridge: synopsys: dw-dp: Add missing reinit_completion
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
The DP AUX transfer method uses a completion triggered by an interrupt,
which can timeout. If the function runs into the timeout and the
interrupt fires afterwards, the following DP aux transfer completion
would trigger immediately without waiting for the interrupt. This in
turn means the next one would also be broken and so on.
Fix this potential issue by re-initializing the completion before
sending the AUX command.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index b28040d69fab..2f0ee7ab7feb 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1465,6 +1465,8 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
if (WARN_ON(msg->size > 16))
return -E2BIG;
+ reinit_completion(&dp->complete);
+
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 04/16] drm/bridge: synopsys: dw-dp: Add missing reinit_completion
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:21 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:21 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: dri-devel, robh, conor+dt, devicetree
Thank you for your contribution! Sashiko AI review found 5 potential issue(s) to consider:
Pre-existing issues:
- [High] The patch attempts to fix spurious completions from timed-out AUX transfers by adding `reinit_completion()`, but the fix is insufficient due to a TOCTOU race with the driver's threaded IRQ handler.
- [High] The driver fails to support DP AUX short reads, incorrectly rejecting them with -EBUSY instead of returning the number of bytes successfully transferred, which breaks I2C-over-AUX.
- [High] Missing hardware reset on AUX transfer timeout leaves the controller in an undefined/busy state.
- [High] The DP AUX channel and I2C adapter are registered and exposed before the hardware is initialized and interrupts are enabled, causing early access to fail with timeouts.
- [High] DP AUX transfers can execute with the PHY powered off, leading to hardware timeouts or crashes.
--
--- Patch [4]: [PATCH v6 04/16] drm/bridge: synopsys: dw-dp: Add missing reinit_completion ---
commit fc6159d600f530845f6f08962e449b720526ee08
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/bridge: synopsys: dw-dp: Add missing reinit_completion
This patch adds a reinit_completion call before sending an AUX command
to prevent subsequent transfers from immediately triggering if an earlier
one timed out and the interrupt fired later.
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> index b28040d69fabf..2f0ee7ab7febd 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> @@ -1465,6 +1465,8 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
> if (WARN_ON(msg->size > 16))
> return -E2BIG;
>
> + reinit_completion(&dp->complete);
> +
[Severity: High]
This isn't a bug introduced by this patch, but the attempt to fix the
spurious completions seems incomplete due to a race condition. Because
reinit_completion is called locklessly here, could the threaded IRQ handler
execute concurrently?
If dw_dp_irq is processing a delayed interrupt from a previous timeout:
dw_dp_irq() {
...
complete(&dp->complete);
}
Doesn't this mean it could call complete immediately after this
reinit_completion, instantly satisfying the new wait and causing the driver
to read garbage hardware status?
> switch (msg->request & ~DP_AUX_I2C_MOT) {
> case DP_AUX_NATIVE_WRITE:
> case DP_AUX_I2C_WRITE:
[Severity: High]
This is a pre-existing issue, but does this driver fail to support DP AUX
short reads?
Later in dw_dp_aux_transfer:
if (count != msg->size)
return -EBUSY;
If the hardware returns fewer bytes than requested, returning -EBUSY causes
the DRM core helper drm_dp_i2c_do_msg to endlessly retry the exact same
full-length transfer without advancing its buffer. Could this break
communication with I2C devices on the DP bus?
[Severity: High]
This is a pre-existing issue, but is a hardware reset missing when an AUX
transfer times out?
In the error path of dw_dp_aux_transfer:
if (!status) {
dev_err(dp->dev, "timeout waiting for AUX reply\n");
return -ETIMEDOUT;
}
If wait_for_completion_timeout expires, returning -ETIMEDOUT without
resetting the underlying AUX controller or clearing the pending state might
leave the hardware state machine permanently stuck. Will subsequent transfers
fail because the hardware is still busy?
[Severity: High]
This isn't a bug introduced by this patch, but is the AUX channel registered
before interrupts are enabled?
Looking at dw_dp_bind, the channel is registered early:
ret = drm_dp_aux_register(&dp->aux);
But interrupts are enabled much later in the same function:
enable_irq(dp->irq);
If a userspace tool like ddcutil or an I2C auto-prober attempts a transaction
in this window, won't dw_dp_aux_transfer fail because the hardware cannot
yet generate interrupts?
[Severity: High]
This is a pre-existing issue, but can DP AUX transfers execute with the PHY
powered off?
Direct accesses from userspace via the character device call directly into:
static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg)
Internal callers wrap this to ensure the PHY is powered on:
dw_dp_bridge_edid_read() {
...
ret = phy_power_on(dp->phy);
if (ret)
return NULL;
edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
phy_power_off(dp->phy);
...
}
Since dw_dp_aux_transfer itself doesn't check or manage the PHY power state,
could a direct userspace access while the display is suspended cause MMIO
timeouts or system crashes?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=4
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 05/16] drm/bridge: synopsys: dw-dp: Free output_fmts when none are valid
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
Sashiko, kernel, linux-arm-kernel
If dw_dp_bandwidth_ok() returns false for all formats, *num_output_fmts
might end up becoming 0. In this case functions calling it assume that
nothing needs to be free'd, so free output_fmts within the function to
avoid leaking memory.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 2f0ee7ab7feb..7f6506f8d4bd 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1797,6 +1797,11 @@ static u32 *dw_dp_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
output_fmts[j++] = fmt->bus_format;
}
+ if (j == 0) {
+ kfree(output_fmts);
+ output_fmts = NULL;
+ }
+
*num_output_fmts = j;
return output_fmts;
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 05/16] drm/bridge: synopsys: dw-dp: Free output_fmts when none are valid
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel, Sashiko
If dw_dp_bandwidth_ok() returns false for all formats, *num_output_fmts
might end up becoming 0. In this case functions calling it assume that
nothing needs to be free'd, so free output_fmts within the function to
avoid leaking memory.
Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support library")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 2f0ee7ab7feb..7f6506f8d4bd 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1797,6 +1797,11 @@ static u32 *dw_dp_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
output_fmts[j++] = fmt->bus_format;
}
+ if (j == 0) {
+ kfree(output_fmts);
+ output_fmts = NULL;
+ }
+
*num_output_fmts = j;
return output_fmts;
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 06/16] drm/bridge: synopsys: dw-dp: Support MEDIA_BUS_FMT_FIXED
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Add support for MEDIA_BUS_FMT_FIXED, which is e.g. requested for USB-C
DP chains as the last bridge in the chain (aux-hpd-bridge) does not
implement atomic_get_output_bus_fmts(), which results in the generic
drm_atomic_bridge_chain_select_bus_fmts() code using MEDIA_BUS_FMT_FIXED
instead. For decent support of this, two areas are changed:
1. In atomic_check, resolving MEDIA_BUS_FMT_FIXED output format by
using the negotiated input format.
2. Implementing a custom .atomic_get_input_bus_fmts hook that, on
MEDIA_BUS_FMT_FIXED, advertises all bandwidth-validated formats
from dw_dp_bridge_atomic_get_output_bus_fmts(). This lets the
upstream encoder negotiate the best mutually supported format.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 34 +++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 7f6506f8d4bd..259efc25b56e 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1530,6 +1530,7 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
struct drm_connector_state *conn_state)
{
struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+ unsigned int out_bus_format = bridge_state->output_bus_cfg.format;
struct dw_dp *dp = bridge_to_dp(bridge);
struct dw_dp_bridge_state *state;
const struct dw_dp_output_format *fmt;
@@ -1540,7 +1541,10 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
state = to_dw_dp_bridge_state(bridge_state);
mode = &state->mode;
- fmt = dw_dp_get_output_format(bridge_state->output_bus_cfg.format);
+ if (out_bus_format == MEDIA_BUS_FMT_FIXED)
+ out_bus_format = bridge_state->input_bus_cfg.format;
+
+ fmt = dw_dp_get_output_format(out_bus_format);
if (!fmt)
return -EINVAL;
@@ -1807,6 +1811,32 @@ static u32 *dw_dp_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
return output_fmts;
}
+static u32 *
+dw_dp_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts)
+{
+ /*
+ * MEDIA_BUS_FMT_FIXED means the downstream bridge does not constrain
+ * the bus format. In that case, advertise all formats supported by the
+ * DP link so the upstream encoder can negotiate the best match.
+ */
+ if (output_fmt == MEDIA_BUS_FMT_FIXED)
+ return dw_dp_bridge_atomic_get_output_bus_fmts(bridge,
+ bridge_state,
+ crtc_state,
+ conn_state,
+ num_input_fmts);
+
+ return drm_atomic_helper_bridge_propagate_bus_fmt(bridge, bridge_state,
+ crtc_state, conn_state,
+ output_fmt,
+ num_input_fmts);
+}
+
static struct drm_bridge_state *dw_dp_bridge_atomic_duplicate_state(struct drm_bridge *bridge)
{
struct dw_dp_bridge_state *state;
@@ -1824,7 +1854,7 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
.atomic_create_state = drm_atomic_helper_bridge_create_state,
- .atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
+ .atomic_get_input_bus_fmts = dw_dp_bridge_atomic_get_input_bus_fmts,
.atomic_get_output_bus_fmts = dw_dp_bridge_atomic_get_output_bus_fmts,
.atomic_check = dw_dp_bridge_atomic_check,
.mode_valid = dw_dp_bridge_mode_valid,
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 06/16] drm/bridge: synopsys: dw-dp: Support MEDIA_BUS_FMT_FIXED
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Add support for MEDIA_BUS_FMT_FIXED, which is e.g. requested for USB-C
DP chains as the last bridge in the chain (aux-hpd-bridge) does not
implement atomic_get_output_bus_fmts(), which results in the generic
drm_atomic_bridge_chain_select_bus_fmts() code using MEDIA_BUS_FMT_FIXED
instead. For decent support of this, two areas are changed:
1. In atomic_check, resolving MEDIA_BUS_FMT_FIXED output format by
using the negotiated input format.
2. Implementing a custom .atomic_get_input_bus_fmts hook that, on
MEDIA_BUS_FMT_FIXED, advertises all bandwidth-validated formats
from dw_dp_bridge_atomic_get_output_bus_fmts(). This lets the
upstream encoder negotiate the best mutually supported format.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 34 +++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 7f6506f8d4bd..259efc25b56e 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1530,6 +1530,7 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
struct drm_connector_state *conn_state)
{
struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+ unsigned int out_bus_format = bridge_state->output_bus_cfg.format;
struct dw_dp *dp = bridge_to_dp(bridge);
struct dw_dp_bridge_state *state;
const struct dw_dp_output_format *fmt;
@@ -1540,7 +1541,10 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
state = to_dw_dp_bridge_state(bridge_state);
mode = &state->mode;
- fmt = dw_dp_get_output_format(bridge_state->output_bus_cfg.format);
+ if (out_bus_format == MEDIA_BUS_FMT_FIXED)
+ out_bus_format = bridge_state->input_bus_cfg.format;
+
+ fmt = dw_dp_get_output_format(out_bus_format);
if (!fmt)
return -EINVAL;
@@ -1807,6 +1811,32 @@ static u32 *dw_dp_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
return output_fmts;
}
+static u32 *
+dw_dp_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts)
+{
+ /*
+ * MEDIA_BUS_FMT_FIXED means the downstream bridge does not constrain
+ * the bus format. In that case, advertise all formats supported by the
+ * DP link so the upstream encoder can negotiate the best match.
+ */
+ if (output_fmt == MEDIA_BUS_FMT_FIXED)
+ return dw_dp_bridge_atomic_get_output_bus_fmts(bridge,
+ bridge_state,
+ crtc_state,
+ conn_state,
+ num_input_fmts);
+
+ return drm_atomic_helper_bridge_propagate_bus_fmt(bridge, bridge_state,
+ crtc_state, conn_state,
+ output_fmt,
+ num_input_fmts);
+}
+
static struct drm_bridge_state *dw_dp_bridge_atomic_duplicate_state(struct drm_bridge *bridge)
{
struct dw_dp_bridge_state *state;
@@ -1824,7 +1854,7 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
.atomic_create_state = drm_atomic_helper_bridge_create_state,
- .atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
+ .atomic_get_input_bus_fmts = dw_dp_bridge_atomic_get_input_bus_fmts,
.atomic_get_output_bus_fmts = dw_dp_bridge_atomic_get_output_bus_fmts,
.atomic_check = dw_dp_bridge_atomic_check,
.mode_valid = dw_dp_bridge_mode_valid,
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 07/16] drm/bridge: synopsys: dw-dp: Add follow-up bridge support
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Add support to use USB-C connectors with the DP altmode helper code on
devicetree based platforms. To get this working there must be a DRM
bridge chain from the DisplayPort controller to the USB-C connector.
E.g. on Rockchip RK3576:
root@rk3576 # cat /sys/kernel/debug/dri/0/encoder-0/bridges
bridge[0]: dw_dp_bridge_funcs
refcount: 7
type: [10] DP
OF: /soc/dp@27e40000:rockchip,rk3576-dp
ops: [0x47] detect edid hpd
bridge[1]: drm_aux_bridge_funcs
refcount: 4
type: [0] Unknown
OF: /soc/phy@2b010000:rockchip,rk3576-usbdp-phy
ops: [0x0]
bridge[2]: drm_aux_hpd_bridge_funcs
refcount: 5
type: [10] DP
OF: /soc/i2c@2ac50000/typec-portc@22/connector:usb-c-connector
ops: [0x4] hpd
It's fine to fatally error out when there is no follow-up bridge
as the Rockchip Designware Displayport controller is the only
user of the bridge helper and has the port marked as required
in its binding.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 259efc25b56e..591b75c4cc36 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -329,6 +329,8 @@ struct dw_dp {
struct dw_dp_plat_data plat_data;
u8 pixel_mode;
+ struct drm_bridge *next_bridge;
+
DECLARE_BITMAP(sdp_reg_bank, SDP_REG_BANK_SIZE);
};
@@ -2021,18 +2023,35 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto unregister_aux;
}
+ dp->next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 1, 0);
+ if (IS_ERR(dp->next_bridge)) {
+ ret = PTR_ERR(dp->next_bridge);
+ dev_err_probe(dev, ret, "failed to get follow-up bridge.\n");
+ goto unregister_aux;
+ }
+
+ ret = drm_bridge_attach(encoder, dp->next_bridge, bridge,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to attach next bridge\n");
+ goto put_next_bridge;
+ }
+
dw_dp_init_hw(dp);
ret = phy_init(dp->phy);
if (ret) {
dev_err_probe(dev, ret, "phy init failed\n");
- goto unregister_aux;
+ goto put_next_bridge;
}
enable_irq(dp->irq);
return 0;
+put_next_bridge:
+ drm_bridge_put(dp->next_bridge);
+
unregister_aux:
drm_dp_aux_unregister(&dp->aux);
@@ -2048,6 +2067,7 @@ void dw_dp_unbind(struct dw_dp *dp)
disable_irq(dp->irq);
cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
+ drm_bridge_put(dp->next_bridge);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
}
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 07/16] drm/bridge: synopsys: dw-dp: Add follow-up bridge support
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Add support to use USB-C connectors with the DP altmode helper code on
devicetree based platforms. To get this working there must be a DRM
bridge chain from the DisplayPort controller to the USB-C connector.
E.g. on Rockchip RK3576:
root@rk3576 # cat /sys/kernel/debug/dri/0/encoder-0/bridges
bridge[0]: dw_dp_bridge_funcs
refcount: 7
type: [10] DP
OF: /soc/dp@27e40000:rockchip,rk3576-dp
ops: [0x47] detect edid hpd
bridge[1]: drm_aux_bridge_funcs
refcount: 4
type: [0] Unknown
OF: /soc/phy@2b010000:rockchip,rk3576-usbdp-phy
ops: [0x0]
bridge[2]: drm_aux_hpd_bridge_funcs
refcount: 5
type: [10] DP
OF: /soc/i2c@2ac50000/typec-portc@22/connector:usb-c-connector
ops: [0x4] hpd
It's fine to fatally error out when there is no follow-up bridge
as the Rockchip Designware Displayport controller is the only
user of the bridge helper and has the port marked as required
in its binding.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 259efc25b56e..591b75c4cc36 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -329,6 +329,8 @@ struct dw_dp {
struct dw_dp_plat_data plat_data;
u8 pixel_mode;
+ struct drm_bridge *next_bridge;
+
DECLARE_BITMAP(sdp_reg_bank, SDP_REG_BANK_SIZE);
};
@@ -2021,18 +2023,35 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto unregister_aux;
}
+ dp->next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 1, 0);
+ if (IS_ERR(dp->next_bridge)) {
+ ret = PTR_ERR(dp->next_bridge);
+ dev_err_probe(dev, ret, "failed to get follow-up bridge.\n");
+ goto unregister_aux;
+ }
+
+ ret = drm_bridge_attach(encoder, dp->next_bridge, bridge,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to attach next bridge\n");
+ goto put_next_bridge;
+ }
+
dw_dp_init_hw(dp);
ret = phy_init(dp->phy);
if (ret) {
dev_err_probe(dev, ret, "phy init failed\n");
- goto unregister_aux;
+ goto put_next_bridge;
}
enable_irq(dp->irq);
return 0;
+put_next_bridge:
+ drm_bridge_put(dp->next_bridge);
+
unregister_aux:
drm_dp_aux_unregister(&dp->aux);
@@ -2048,6 +2067,7 @@ void dw_dp_unbind(struct dw_dp *dp)
disable_irq(dp->irq);
cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
+ drm_bridge_put(dp->next_bridge);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
}
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 08/16] drm/bridge: Add out-of-band HPD notify handler
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
For DP bridges, that can be used for DP AltMode, it might be necessary
to enforce HPD status. There is an existing ->oob_hotplug_event() on
the DRM connector, but it currently just calls into hpd_notify().
As DP bridge drivers usually also implement .detect and that also
generates calls into hpd_notify, this is a bad place to force the
HPD status as the follow-up detect call might force it off again
resulting in all follow-up calls to the detection routine also
failing.
Avoid this by having a dedicated function for OOB events.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/display/drm_bridge_connector.c | 6 ++++++
include/drm/drm_bridge.h | 14 ++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 8b54069fa53a..632cc3ae3b54 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -180,6 +180,12 @@ static void drm_bridge_connector_oob_hotplug_event(struct drm_connector *connect
struct drm_bridge_connector *bridge_connector =
to_drm_bridge_connector(connector);
+ /* Notify all bridges in the pipeline of hotplug events. */
+ drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge) {
+ if (bridge->funcs->oob_notify)
+ bridge->funcs->oob_notify(bridge, connector, status);
+ }
+
drm_bridge_connector_handle_hpd(bridge_connector, status);
}
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 3ac84ed57ab2..f38010d2edd1 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -540,6 +540,20 @@ struct drm_bridge_funcs {
*/
void (*hpd_disable)(struct drm_bridge *bridge);
+ /**
+ * @oob_notify:
+ *
+ * Notify the bridge of out of band hot plug detection.
+ *
+ * This callback is optional, it may be implemented by bridges that
+ * need to be notified of display connection or disconnection for
+ * internal reasons. One use case is to force the DP controllers HPD
+ * signal for USB-C DP AltMode.
+ */
+ void (*oob_notify)(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ enum drm_connector_status status);
+
/**
* @hdmi_tmds_char_rate_valid:
*
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 08/16] drm/bridge: Add out-of-band HPD notify handler
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
For DP bridges, that can be used for DP AltMode, it might be necessary
to enforce HPD status. There is an existing ->oob_hotplug_event() on
the DRM connector, but it currently just calls into hpd_notify().
As DP bridge drivers usually also implement .detect and that also
generates calls into hpd_notify, this is a bad place to force the
HPD status as the follow-up detect call might force it off again
resulting in all follow-up calls to the detection routine also
failing.
Avoid this by having a dedicated function for OOB events.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/display/drm_bridge_connector.c | 6 ++++++
include/drm/drm_bridge.h | 14 ++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 8b54069fa53a..632cc3ae3b54 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -180,6 +180,12 @@ static void drm_bridge_connector_oob_hotplug_event(struct drm_connector *connect
struct drm_bridge_connector *bridge_connector =
to_drm_bridge_connector(connector);
+ /* Notify all bridges in the pipeline of hotplug events. */
+ drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge) {
+ if (bridge->funcs->oob_notify)
+ bridge->funcs->oob_notify(bridge, connector, status);
+ }
+
drm_bridge_connector_handle_hpd(bridge_connector, status);
}
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 3ac84ed57ab2..f38010d2edd1 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -540,6 +540,20 @@ struct drm_bridge_funcs {
*/
void (*hpd_disable)(struct drm_bridge *bridge);
+ /**
+ * @oob_notify:
+ *
+ * Notify the bridge of out of band hot plug detection.
+ *
+ * This callback is optional, it may be implemented by bridges that
+ * need to be notified of display connection or disconnection for
+ * internal reasons. One use case is to force the DP controllers HPD
+ * signal for USB-C DP AltMode.
+ */
+ void (*oob_notify)(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ enum drm_connector_status status);
+
/**
* @hdmi_tmds_char_rate_valid:
*
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 09/16] drm/bridge: synopsys: dw-dp: Support software triggered OOB HPD
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Add support for USB-C DP AltMode out-of-band hotplug handling. The
handling itself is implemented in the platform specific driver as the
registers to force HPD state are not part of the Designware DisplayPort
IP itself. Instead the platform integration might provide the necessary
functionality to mux the HPD signal.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 38 +++++++++++++++++++++++++++++++++
include/drm/bridge/dw_dp.h | 3 +++
2 files changed, 41 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 591b75c4cc36..2042bc00f906 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1852,6 +1852,19 @@ static struct drm_bridge_state *dw_dp_bridge_atomic_duplicate_state(struct drm_b
return &state->base;
}
+static void dw_dp_bridge_oob_notify(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ enum drm_connector_status status)
+{
+ bool hpd_high = status != connector_status_disconnected;
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ if (dp->plat_data.hpd_sw_cfg)
+ dp->plat_data.hpd_sw_cfg(dp->plat_data.data, hpd_high);
+ else
+ dev_err_once(dp->dev, "Missing platform handler for OOB HPD handling\n");
+}
+
static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
@@ -1864,6 +1877,7 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_disable = dw_dp_bridge_atomic_disable,
.detect = dw_dp_bridge_detect,
.edid_read = dw_dp_bridge_edid_read,
+ .oob_notify = dw_dp_bridge_oob_notify,
};
static int dw_dp_link_retrain(struct dw_dp *dp)
@@ -1993,6 +2007,19 @@ static const struct regmap_config dw_dp_regmap_config = {
.rd_table = &dw_dp_readable_table,
};
+static bool dw_dp_is_routed_to_usb_c(struct drm_encoder *encoder)
+{
+ struct drm_bridge *last_bridge __free(drm_bridge_put) = NULL;
+ struct fwnode_handle *fwnode;
+
+ last_bridge = drm_bridge_chain_get_last_bridge(encoder);
+ if (!last_bridge)
+ return false;
+
+ fwnode = of_fwnode_handle(last_bridge->of_node);
+ return fwnode_device_is_compatible(fwnode, "usb-c-connector");
+}
+
int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
{
struct device *dev = dp->dev;
@@ -2037,6 +2064,13 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto put_next_bridge;
}
+ if (dw_dp_is_routed_to_usb_c(encoder)) {
+ dev_dbg(dev, "USB-C mode\n");
+
+ if (dp->plat_data.hpd_sw_sel)
+ dp->plat_data.hpd_sw_sel(dp->plat_data.data, 1);
+ }
+
dw_dp_init_hw(dp);
ret = phy_init(dp->phy);
@@ -2086,6 +2120,10 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
dp->dev = dev;
dp->pixel_mode = plat_data->pixel_mode;
+
+ dp->plat_data.hpd_sw_sel = plat_data->hpd_sw_sel;
+ dp->plat_data.hpd_sw_cfg = plat_data->hpd_sw_cfg;
+ dp->plat_data.data = plat_data->data;
dp->plat_data.max_link_rate = plat_data->max_link_rate;
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index a82412a9e769..79b2cdf0df99 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -20,6 +20,9 @@ enum {
struct dw_dp_plat_data {
u32 max_link_rate;
u8 pixel_mode;
+ void *data;
+ void (*hpd_sw_sel)(void *data, bool hpd);
+ void (*hpd_sw_cfg)(void *data, bool hpd);
};
int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 09/16] drm/bridge: synopsys: dw-dp: Support software triggered OOB HPD
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Add support for USB-C DP AltMode out-of-band hotplug handling. The
handling itself is implemented in the platform specific driver as the
registers to force HPD state are not part of the Designware DisplayPort
IP itself. Instead the platform integration might provide the necessary
functionality to mux the HPD signal.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 38 +++++++++++++++++++++++++++++++++
include/drm/bridge/dw_dp.h | 3 +++
2 files changed, 41 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 591b75c4cc36..2042bc00f906 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1852,6 +1852,19 @@ static struct drm_bridge_state *dw_dp_bridge_atomic_duplicate_state(struct drm_b
return &state->base;
}
+static void dw_dp_bridge_oob_notify(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ enum drm_connector_status status)
+{
+ bool hpd_high = status != connector_status_disconnected;
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ if (dp->plat_data.hpd_sw_cfg)
+ dp->plat_data.hpd_sw_cfg(dp->plat_data.data, hpd_high);
+ else
+ dev_err_once(dp->dev, "Missing platform handler for OOB HPD handling\n");
+}
+
static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
@@ -1864,6 +1877,7 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_disable = dw_dp_bridge_atomic_disable,
.detect = dw_dp_bridge_detect,
.edid_read = dw_dp_bridge_edid_read,
+ .oob_notify = dw_dp_bridge_oob_notify,
};
static int dw_dp_link_retrain(struct dw_dp *dp)
@@ -1993,6 +2007,19 @@ static const struct regmap_config dw_dp_regmap_config = {
.rd_table = &dw_dp_readable_table,
};
+static bool dw_dp_is_routed_to_usb_c(struct drm_encoder *encoder)
+{
+ struct drm_bridge *last_bridge __free(drm_bridge_put) = NULL;
+ struct fwnode_handle *fwnode;
+
+ last_bridge = drm_bridge_chain_get_last_bridge(encoder);
+ if (!last_bridge)
+ return false;
+
+ fwnode = of_fwnode_handle(last_bridge->of_node);
+ return fwnode_device_is_compatible(fwnode, "usb-c-connector");
+}
+
int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
{
struct device *dev = dp->dev;
@@ -2037,6 +2064,13 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto put_next_bridge;
}
+ if (dw_dp_is_routed_to_usb_c(encoder)) {
+ dev_dbg(dev, "USB-C mode\n");
+
+ if (dp->plat_data.hpd_sw_sel)
+ dp->plat_data.hpd_sw_sel(dp->plat_data.data, 1);
+ }
+
dw_dp_init_hw(dp);
ret = phy_init(dp->phy);
@@ -2086,6 +2120,10 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
dp->dev = dev;
dp->pixel_mode = plat_data->pixel_mode;
+
+ dp->plat_data.hpd_sw_sel = plat_data->hpd_sw_sel;
+ dp->plat_data.hpd_sw_cfg = plat_data->hpd_sw_cfg;
+ dp->plat_data.data = plat_data->data;
dp->plat_data.max_link_rate = plat_data->max_link_rate;
INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index a82412a9e769..79b2cdf0df99 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -20,6 +20,9 @@ enum {
struct dw_dp_plat_data {
u32 max_link_rate;
u8 pixel_mode;
+ void *data;
+ void (*hpd_sw_sel)(void *data, bool hpd);
+ void (*hpd_sw_cfg)(void *data, bool hpd);
};
int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 10/16] drm/rockchip: dw_dp: Implement out-of-band HPD handling
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Implement out-of-band hotplug handling, which will be used to receive
external hotplug information from the USB-C state machine. This is
currently handled by the USBDP PHY, which brings quite some trouble
as the register being accessed requires the power-domain from the DP
controller. Thus this patch prevents massive SError problems once
runtime PM is enabled. Apart from that it avoids custom TypeC HPD
info parsing in the USBDP PHY driver.
In contrast to the USBDP PHY this does not just enable the hotplug
signal when a DP AltMode capable adapter is plugged in, but instead
properly detects if a cable is plugged in for things like USB-C to
HDMI adapters.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 124 ++++++++++++++++++++++++++++--
1 file changed, 119 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index 005938dc66c9..ee0bd696064e 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -7,9 +7,12 @@
*/
#include <linux/component.h>
+#include <linux/hw_bitfield.h>
#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/videodev2.h>
#include <drm/bridge/dw_dp.h>
@@ -23,12 +26,54 @@
#include "rockchip_drm_drv.h"
+#define ROCKCHIP_MAX_CTRLS 2
+
+#define ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL BIT(10)
+#define ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG BIT(11)
+
+struct rockchip_dw_dp_plat_data {
+ u8 num_ctrls;
+ u32 ctrl_ids[ROCKCHIP_MAX_CTRLS];
+ u32 max_link_rate;
+ u8 pixel_mode;
+ u32 hpd_reg[ROCKCHIP_MAX_CTRLS];
+};
+
struct rockchip_dw_dp {
struct dw_dp *base;
struct device *dev;
+ const struct rockchip_dw_dp_plat_data *pdata;
+ struct regmap *vo_grf;
struct rockchip_encoder *encoder;
+ int id;
+ bool hpd_sel;
+ bool hpd_cfg;
};
+static void dw_dp_rockchip_hpd_sw_sel(void *data, bool force_hpd_from_sw)
+{
+ struct rockchip_dw_dp *dp = data;
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+
+ dp->hpd_sel = force_hpd_from_sw;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel));
+}
+
+static void dw_dp_rockchip_hpd_sw_cfg(void *data, bool hpd)
+{
+ struct rockchip_dw_dp *dp = data;
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+
+ dev_dbg(dp->dev, "Force HPD connected=%s\n", str_yes_no(hpd));
+
+ dp->hpd_cfg = hpd;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
+}
+
static int dw_dp_encoder_atomic_check(struct drm_encoder *encoder,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
@@ -71,6 +116,35 @@ static const struct drm_encoder_helper_funcs dw_dp_encoder_helper_funcs = {
.atomic_check = dw_dp_encoder_atomic_check,
};
+static struct regmap *dp_dp_rockchip_get_vo_grf(struct rockchip_dw_dp *dp)
+{
+ struct device_node *np = dev_of_node(dp->dev);
+ struct of_phandle_args args;
+ struct regmap *regmap;
+ int ret;
+
+ ret = of_parse_phandle_with_args(np, "phys", "#phy-cells", 0, &args);
+ if (ret)
+ return ERR_PTR(-ENODEV);
+
+ /*
+ * Limit this workaround to RK3576 and RK3588, potential future platforms
+ * reusing the driver should just add a VO GRF phandle in the DisplayPort
+ * controller DT node.
+ */
+ if (!of_device_is_compatible(args.np, "rockchip,rk3576-usbdp-phy") &&
+ !of_device_is_compatible(args.np, "rockchip,rk3588-usbdp-phy")) {
+ regmap = ERR_PTR(-ENODEV);
+ goto out_put_node;
+ }
+
+ regmap = syscon_regmap_lookup_by_phandle(args.np, "rockchip,vo-grf");
+
+out_put_node:
+ of_node_put(args.np);
+ return regmap;
+}
+
static int dw_dp_rockchip_bind(struct device *dev, struct device *master, void *data)
{
struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
@@ -121,19 +195,53 @@ static const struct component_ops dw_dp_rockchip_component_ops = {
static int dw_dp_rockchip_probe(struct platform_device *pdev)
{
- const struct dw_dp_plat_data *plat_data;
+ const struct rockchip_dw_dp_plat_data *plat_data_const;
+ struct dw_dp_plat_data *plat_data;
struct device *dev = &pdev->dev;
struct rockchip_dw_dp *dp;
+ struct resource *res;
+ int id;
- plat_data = of_device_get_match_data(dev);
- if (!plat_data)
+ plat_data_const = device_get_match_data(dev);
+ if (!plat_data_const)
return -ENODEV;
+ plat_data = devm_kzalloc(dev, sizeof(*plat_data), GFP_KERNEL);
+ if (!plat_data)
+ return -ENOMEM;
+
dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
if (!dp)
return -ENOMEM;
platform_set_drvdata(pdev, dp);
dp->dev = dev;
+ dp->pdata = plat_data_const;
+
+ res = platform_get_mem_or_io(pdev, 0);
+ if (!res)
+ return -ENODEV;
+
+ /* find the DisplayPort ID from the io address */
+ dp->id = -ENODEV;
+ for (id = 0; id < plat_data_const->num_ctrls; id++) {
+ if (res->start == plat_data_const->ctrl_ids[id]) {
+ dp->id = id;
+ break;
+ }
+ }
+
+ if (dp->id < 0)
+ return dp->id;
+
+ dp->vo_grf = dp_dp_rockchip_get_vo_grf(dp);
+ if (IS_ERR(dp->vo_grf))
+ return PTR_ERR(dp->vo_grf);
+
+ plat_data->max_link_rate = plat_data_const->max_link_rate;
+ plat_data->pixel_mode = plat_data_const->pixel_mode;
+ plat_data->hpd_sw_sel = dw_dp_rockchip_hpd_sw_sel;
+ plat_data->hpd_sw_cfg = dw_dp_rockchip_hpd_sw_cfg;
+ plat_data->data = dp;
dp->base = dw_dp_probe(pdev, plat_data);
if (IS_ERR(dp->base))
@@ -147,14 +255,20 @@ static void dw_dp_rockchip_remove(struct platform_device *pdev)
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
-static const struct dw_dp_plat_data rk3588_dp_plat_data = {
+static const struct rockchip_dw_dp_plat_data rk3588_dp_plat_data = {
+ .num_ctrls = 2,
+ .ctrl_ids = {0xfde50000, 0xfde60000},
.max_link_rate = 810000,
.pixel_mode = DW_DP_MP_QUAD_PIXEL,
+ .hpd_reg = {0x0000, 0x0008},
};
-static const struct dw_dp_plat_data rk3576_dp_plat_data = {
+static const struct rockchip_dw_dp_plat_data rk3576_dp_plat_data = {
+ .num_ctrls = 1,
+ .ctrl_ids = {0x27e40000},
.max_link_rate = 810000,
.pixel_mode = DW_DP_MP_DUAL_PIXEL,
+ .hpd_reg = {0x0000},
};
static const struct of_device_id dw_dp_of_match[] = {
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 10/16] drm/rockchip: dw_dp: Implement out-of-band HPD handling
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Implement out-of-band hotplug handling, which will be used to receive
external hotplug information from the USB-C state machine. This is
currently handled by the USBDP PHY, which brings quite some trouble
as the register being accessed requires the power-domain from the DP
controller. Thus this patch prevents massive SError problems once
runtime PM is enabled. Apart from that it avoids custom TypeC HPD
info parsing in the USBDP PHY driver.
In contrast to the USBDP PHY this does not just enable the hotplug
signal when a DP AltMode capable adapter is plugged in, but instead
properly detects if a cable is plugged in for things like USB-C to
HDMI adapters.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 124 ++++++++++++++++++++++++++++--
1 file changed, 119 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index 005938dc66c9..ee0bd696064e 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -7,9 +7,12 @@
*/
#include <linux/component.h>
+#include <linux/hw_bitfield.h>
#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/videodev2.h>
#include <drm/bridge/dw_dp.h>
@@ -23,12 +26,54 @@
#include "rockchip_drm_drv.h"
+#define ROCKCHIP_MAX_CTRLS 2
+
+#define ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL BIT(10)
+#define ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG BIT(11)
+
+struct rockchip_dw_dp_plat_data {
+ u8 num_ctrls;
+ u32 ctrl_ids[ROCKCHIP_MAX_CTRLS];
+ u32 max_link_rate;
+ u8 pixel_mode;
+ u32 hpd_reg[ROCKCHIP_MAX_CTRLS];
+};
+
struct rockchip_dw_dp {
struct dw_dp *base;
struct device *dev;
+ const struct rockchip_dw_dp_plat_data *pdata;
+ struct regmap *vo_grf;
struct rockchip_encoder *encoder;
+ int id;
+ bool hpd_sel;
+ bool hpd_cfg;
};
+static void dw_dp_rockchip_hpd_sw_sel(void *data, bool force_hpd_from_sw)
+{
+ struct rockchip_dw_dp *dp = data;
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+
+ dp->hpd_sel = force_hpd_from_sw;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel));
+}
+
+static void dw_dp_rockchip_hpd_sw_cfg(void *data, bool hpd)
+{
+ struct rockchip_dw_dp *dp = data;
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+
+ dev_dbg(dp->dev, "Force HPD connected=%s\n", str_yes_no(hpd));
+
+ dp->hpd_cfg = hpd;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
+}
+
static int dw_dp_encoder_atomic_check(struct drm_encoder *encoder,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
@@ -71,6 +116,35 @@ static const struct drm_encoder_helper_funcs dw_dp_encoder_helper_funcs = {
.atomic_check = dw_dp_encoder_atomic_check,
};
+static struct regmap *dp_dp_rockchip_get_vo_grf(struct rockchip_dw_dp *dp)
+{
+ struct device_node *np = dev_of_node(dp->dev);
+ struct of_phandle_args args;
+ struct regmap *regmap;
+ int ret;
+
+ ret = of_parse_phandle_with_args(np, "phys", "#phy-cells", 0, &args);
+ if (ret)
+ return ERR_PTR(-ENODEV);
+
+ /*
+ * Limit this workaround to RK3576 and RK3588, potential future platforms
+ * reusing the driver should just add a VO GRF phandle in the DisplayPort
+ * controller DT node.
+ */
+ if (!of_device_is_compatible(args.np, "rockchip,rk3576-usbdp-phy") &&
+ !of_device_is_compatible(args.np, "rockchip,rk3588-usbdp-phy")) {
+ regmap = ERR_PTR(-ENODEV);
+ goto out_put_node;
+ }
+
+ regmap = syscon_regmap_lookup_by_phandle(args.np, "rockchip,vo-grf");
+
+out_put_node:
+ of_node_put(args.np);
+ return regmap;
+}
+
static int dw_dp_rockchip_bind(struct device *dev, struct device *master, void *data)
{
struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
@@ -121,19 +195,53 @@ static const struct component_ops dw_dp_rockchip_component_ops = {
static int dw_dp_rockchip_probe(struct platform_device *pdev)
{
- const struct dw_dp_plat_data *plat_data;
+ const struct rockchip_dw_dp_plat_data *plat_data_const;
+ struct dw_dp_plat_data *plat_data;
struct device *dev = &pdev->dev;
struct rockchip_dw_dp *dp;
+ struct resource *res;
+ int id;
- plat_data = of_device_get_match_data(dev);
- if (!plat_data)
+ plat_data_const = device_get_match_data(dev);
+ if (!plat_data_const)
return -ENODEV;
+ plat_data = devm_kzalloc(dev, sizeof(*plat_data), GFP_KERNEL);
+ if (!plat_data)
+ return -ENOMEM;
+
dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
if (!dp)
return -ENOMEM;
platform_set_drvdata(pdev, dp);
dp->dev = dev;
+ dp->pdata = plat_data_const;
+
+ res = platform_get_mem_or_io(pdev, 0);
+ if (!res)
+ return -ENODEV;
+
+ /* find the DisplayPort ID from the io address */
+ dp->id = -ENODEV;
+ for (id = 0; id < plat_data_const->num_ctrls; id++) {
+ if (res->start == plat_data_const->ctrl_ids[id]) {
+ dp->id = id;
+ break;
+ }
+ }
+
+ if (dp->id < 0)
+ return dp->id;
+
+ dp->vo_grf = dp_dp_rockchip_get_vo_grf(dp);
+ if (IS_ERR(dp->vo_grf))
+ return PTR_ERR(dp->vo_grf);
+
+ plat_data->max_link_rate = plat_data_const->max_link_rate;
+ plat_data->pixel_mode = plat_data_const->pixel_mode;
+ plat_data->hpd_sw_sel = dw_dp_rockchip_hpd_sw_sel;
+ plat_data->hpd_sw_cfg = dw_dp_rockchip_hpd_sw_cfg;
+ plat_data->data = dp;
dp->base = dw_dp_probe(pdev, plat_data);
if (IS_ERR(dp->base))
@@ -147,14 +255,20 @@ static void dw_dp_rockchip_remove(struct platform_device *pdev)
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
-static const struct dw_dp_plat_data rk3588_dp_plat_data = {
+static const struct rockchip_dw_dp_plat_data rk3588_dp_plat_data = {
+ .num_ctrls = 2,
+ .ctrl_ids = {0xfde50000, 0xfde60000},
.max_link_rate = 810000,
.pixel_mode = DW_DP_MP_QUAD_PIXEL,
+ .hpd_reg = {0x0000, 0x0008},
};
-static const struct dw_dp_plat_data rk3576_dp_plat_data = {
+static const struct rockchip_dw_dp_plat_data rk3576_dp_plat_data = {
+ .num_ctrls = 1,
+ .ctrl_ids = {0x27e40000},
.max_link_rate = 810000,
.pixel_mode = DW_DP_MP_DUAL_PIXEL,
+ .hpd_reg = {0x0000},
};
static const struct of_device_id dw_dp_of_match[] = {
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 10/16] drm/rockchip: dw_dp: Implement out-of-band HPD handling
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:27 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:27 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: conor+dt, devicetree, dri-devel, robh
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] Broken forward compatibility in dp_dp_rockchip_get_vo_grf.
- [Low] Typo in the newly introduced function name `dp_dp_rockchip_get_vo_grf`.
--
--- Patch [10]: [PATCH v6 10/16] drm/rockchip: dw_dp: Implement out-of-band HPD handling ---
commit 75a9965306b4d818663f8d48b44dc43031d1cb8f
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/rockchip: dw_dp: Implement out-of-band HPD handling
This commit implements out-of-band hotplug handling to receive external HPD
information from the USB-C state machine via a syscon regmap (vo-grf). It
prevents SError problems on RK3576/RK3588 platforms when runtime PM is
enabled.
> diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
> --- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
[ ... ]
> @@ -71,6 +116,35 @@ static const struct drm_encoder_helper_funcs dw_dp_encoder_helper_funcs = {
> .atomic_check = dw_dp_encoder_atomic_check,
> };
>
> +static struct regmap *dp_dp_rockchip_get_vo_grf(struct rockchip_dw_dp *dp)
^^^^^^^^^^^^^^^^^^^^^^^^^
[Severity: Low]
This isn't a bug, but there is a typo in the function prefix. Should this be
named dw_dp_rockchip_get_vo_grf to match the rest of the driver's naming
conventions?
> +{
> + struct device_node *np = dev_of_node(dp->dev);
> + struct of_phandle_args args;
> + struct regmap *regmap;
> + int ret;
> +
> + ret = of_parse_phandle_with_args(np, "phys", "#phy-cells", 0, &args);
> + if (ret)
> + return ERR_PTR(-ENODEV);
> +
> + /*
> + * Limit this workaround to RK3576 and RK3588, potential future platforms
> + * reusing the driver should just add a VO GRF phandle in the DisplayPort
> + * controller DT node.
> + */
> + if (!of_device_is_compatible(args.np, "rockchip,rk3576-usbdp-phy") &&
> + !of_device_is_compatible(args.np, "rockchip,rk3588-usbdp-phy")) {
> + regmap = ERR_PTR(-ENODEV);
> + goto out_put_node;
> + }
> +
> + regmap = syscon_regmap_lookup_by_phandle(args.np, "rockchip,vo-grf");
[Severity: Medium]
Will this break forward compatibility for future platforms as described in
the comment above?
If a future platform omits the "phys" property or uses a different PHY
compatible, this function unconditionally returns ERR_PTR(-ENODEV) and aborts.
It never attempts to look up the "rockchip,vo-grf" phandle directly from the
DisplayPort controller DT node (np) as a fallback.
Does this need a fallback path to check syscon_regmap_lookup_by_phandle(np, ...)
if the PHY checks fail?
> +
> +out_put_node:
> + of_node_put(args.np);
> + return regmap;
> +}
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=10
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 11/16] drm/bridge: synopsys: dw-dp: Add Runtime PM support
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Add runtime PM stubs to the Synopsys DesignWare DisplayPort bridge
driver. Support is not enabled automatically and must be hooked up
in the vendor specific glue code.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 107 +++++++++++++++++++++++++++++---
include/drm/bridge/dw_dp.h | 3 +
2 files changed, 102 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 2042bc00f906..1bbb39b8d0be 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -328,6 +328,7 @@ struct dw_dp {
struct dw_dp_link link;
struct dw_dp_plat_data plat_data;
u8 pixel_mode;
+ bool usbc_mode;
struct drm_bridge *next_bridge;
@@ -1467,6 +1468,11 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
if (WARN_ON(msg->size > 16))
return -E2BIG;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
reinit_completion(&dp->complete);
switch (msg->request & ~DP_AUX_I2C_MOT) {
@@ -1659,6 +1665,12 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
struct drm_connector_state *conn_state;
int ret;
+ ret = pm_runtime_get_active(dp->dev, RPM_TRANSPARENT);
+ if (ret) {
+ dev_err(dp->dev, "runtime PM failure\n");
+ return;
+ }
+
connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
if (!connector) {
dev_err(dp->dev, "failed to get connector\n");
@@ -1713,6 +1725,7 @@ static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
dw_dp_link_disable(dp);
bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
dw_dp_reset(dp);
+ pm_runtime_put_autosuspend(dp->dev);
}
static bool dw_dp_hpd_detect_link(struct dw_dp *dp, struct drm_connector *connector)
@@ -1733,6 +1746,10 @@ static enum drm_connector_status dw_dp_bridge_detect(struct drm_bridge *bridge,
{
struct dw_dp *dp = bridge_to_dp(bridge);
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+ return connector_status_disconnected;
+
if (!dw_dp_hpd_detect(dp))
return connector_status_disconnected;
@@ -1915,6 +1932,11 @@ static void dw_dp_hpd_work(struct work_struct *work)
bool long_hpd;
int ret;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
mutex_lock(&dp->irq_lock);
long_hpd = dp->hotplug.long_hpd;
mutex_unlock(&dp->irq_lock);
@@ -1966,6 +1988,9 @@ static irqreturn_t dw_dp_irq(int irq, void *data)
struct dw_dp *dp = data;
u32 value;
+ /* interrupt can only trigger for running device */
+ guard(pm_runtime_noresume)(dp->dev);
+
regmap_read(dp->regmap, DW_DP_GENERAL_INTERRUPT, &value);
if (!value)
return IRQ_NONE;
@@ -2064,25 +2089,51 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto put_next_bridge;
}
- if (dw_dp_is_routed_to_usb_c(encoder)) {
- dev_dbg(dev, "USB-C mode\n");
+ dp->usbc_mode = dw_dp_is_routed_to_usb_c(encoder);
- if (dp->plat_data.hpd_sw_sel)
- dp->plat_data.hpd_sw_sel(dp->plat_data.data, 1);
+ ret = pm_runtime_get_active(dev, RPM_TRANSPARENT);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to get runtime PM\n");
+ goto put_next_bridge;
}
- dw_dp_init_hw(dp);
+ /* resume once if runtime PM is disabled */
+ if (!pm_runtime_enabled(dev)) {
+ ret = dw_dp_runtime_resume(dp);
+ if (ret)
+ goto put_runtime_pm;
+ }
+
+ if (dp->plat_data.hpd_sw_sel)
+ dp->plat_data.hpd_sw_sel(dp->plat_data.data, dp->usbc_mode);
ret = phy_init(dp->phy);
if (ret) {
dev_err_probe(dev, ret, "phy init failed\n");
- goto put_next_bridge;
+ goto put_manual_pm;
}
enable_irq(dp->irq);
+ /*
+ * USB-C has out-of-band hotplug detection, so device may enter
+ * runtime suspend. Native mode needs to be resumed for working
+ * hotplug detection.
+ */
+ if (dp->usbc_mode) {
+ dev_dbg(dev, "USB-C mode\n");
+ pm_runtime_put_autosuspend(dp->dev);
+ }
+
return 0;
+put_manual_pm:
+ if (!pm_runtime_enabled(dev))
+ dw_dp_runtime_suspend(dp);
+
+put_runtime_pm:
+ pm_runtime_put_sync(dp->dev);
+
put_next_bridge:
drm_bridge_put(dp->next_bridge);
@@ -2101,6 +2152,11 @@ void dw_dp_unbind(struct dw_dp *dp)
disable_irq(dp->irq);
cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
+ if (!dp->usbc_mode)
+ pm_runtime_put_sync(dp->dev);
+ /* suspend once if runtime PM is disabled */
+ if (!pm_runtime_enabled(dp->dev))
+ dw_dp_runtime_suspend(dp);
drm_bridge_put(dp->next_bridge);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
@@ -2149,13 +2205,13 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
return ERR_CAST(dp->phy);
}
- dp->apb_clk = devm_clk_get_enabled(dev, "apb");
+ dp->apb_clk = devm_clk_get(dev, "apb");
if (IS_ERR(dp->apb_clk)) {
dev_err_probe(dev, PTR_ERR(dp->apb_clk), "failed to get apb clock\n");
return ERR_CAST(dp->apb_clk);
}
- dp->aux_clk = devm_clk_get_enabled(dev, "aux");
+ dp->aux_clk = devm_clk_get(dev, "aux");
if (IS_ERR(dp->aux_clk)) {
dev_err_probe(dev, PTR_ERR(dp->aux_clk), "failed to get aux clock\n");
return ERR_CAST(dp->aux_clk);
@@ -2200,6 +2256,41 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
}
EXPORT_SYMBOL_GPL(dw_dp_probe);
+int dw_dp_runtime_suspend(struct dw_dp *dp)
+{
+ clk_disable_unprepare(dp->aux_clk);
+ clk_disable_unprepare(dp->apb_clk);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_suspend);
+
+int dw_dp_runtime_resume(struct dw_dp *dp)
+{
+ int ret;
+
+ ret = clk_prepare_enable(dp->apb_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(dp->aux_clk);
+ if (ret) {
+ clk_disable_unprepare(dp->apb_clk);
+ return ret;
+ }
+
+ dw_dp_init_hw(dp);
+
+ /*
+ * HPD_HOT_PLUG bit is asserted only after the sink holds HPD
+ * high for at least 100ms.
+ */
+ msleep(110);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_resume);
+
MODULE_AUTHOR("Andy Yan <andyshrk@163.com>");
MODULE_DESCRIPTION("DW DP Core Library");
MODULE_LICENSE("GPL");
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index 79b2cdf0df99..f20d2c2c40ca 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -29,4 +29,7 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
void dw_dp_unbind(struct dw_dp *dp);
struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data);
+
+int dw_dp_runtime_suspend(struct dw_dp *dp);
+int dw_dp_runtime_resume(struct dw_dp *dp);
#endif /* __DW_DP__ */
--
2.53.0
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^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 11/16] drm/bridge: synopsys: dw-dp: Add Runtime PM support
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Add runtime PM stubs to the Synopsys DesignWare DisplayPort bridge
driver. Support is not enabled automatically and must be hooked up
in the vendor specific glue code.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 107 +++++++++++++++++++++++++++++---
include/drm/bridge/dw_dp.h | 3 +
2 files changed, 102 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 2042bc00f906..1bbb39b8d0be 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -328,6 +328,7 @@ struct dw_dp {
struct dw_dp_link link;
struct dw_dp_plat_data plat_data;
u8 pixel_mode;
+ bool usbc_mode;
struct drm_bridge *next_bridge;
@@ -1467,6 +1468,11 @@ static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
if (WARN_ON(msg->size > 16))
return -E2BIG;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
reinit_completion(&dp->complete);
switch (msg->request & ~DP_AUX_I2C_MOT) {
@@ -1659,6 +1665,12 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
struct drm_connector_state *conn_state;
int ret;
+ ret = pm_runtime_get_active(dp->dev, RPM_TRANSPARENT);
+ if (ret) {
+ dev_err(dp->dev, "runtime PM failure\n");
+ return;
+ }
+
connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
if (!connector) {
dev_err(dp->dev, "failed to get connector\n");
@@ -1713,6 +1725,7 @@ static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
dw_dp_link_disable(dp);
bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
dw_dp_reset(dp);
+ pm_runtime_put_autosuspend(dp->dev);
}
static bool dw_dp_hpd_detect_link(struct dw_dp *dp, struct drm_connector *connector)
@@ -1733,6 +1746,10 @@ static enum drm_connector_status dw_dp_bridge_detect(struct drm_bridge *bridge,
{
struct dw_dp *dp = bridge_to_dp(bridge);
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+ return connector_status_disconnected;
+
if (!dw_dp_hpd_detect(dp))
return connector_status_disconnected;
@@ -1915,6 +1932,11 @@ static void dw_dp_hpd_work(struct work_struct *work)
bool long_hpd;
int ret;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
mutex_lock(&dp->irq_lock);
long_hpd = dp->hotplug.long_hpd;
mutex_unlock(&dp->irq_lock);
@@ -1966,6 +1988,9 @@ static irqreturn_t dw_dp_irq(int irq, void *data)
struct dw_dp *dp = data;
u32 value;
+ /* interrupt can only trigger for running device */
+ guard(pm_runtime_noresume)(dp->dev);
+
regmap_read(dp->regmap, DW_DP_GENERAL_INTERRUPT, &value);
if (!value)
return IRQ_NONE;
@@ -2064,25 +2089,51 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
goto put_next_bridge;
}
- if (dw_dp_is_routed_to_usb_c(encoder)) {
- dev_dbg(dev, "USB-C mode\n");
+ dp->usbc_mode = dw_dp_is_routed_to_usb_c(encoder);
- if (dp->plat_data.hpd_sw_sel)
- dp->plat_data.hpd_sw_sel(dp->plat_data.data, 1);
+ ret = pm_runtime_get_active(dev, RPM_TRANSPARENT);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to get runtime PM\n");
+ goto put_next_bridge;
}
- dw_dp_init_hw(dp);
+ /* resume once if runtime PM is disabled */
+ if (!pm_runtime_enabled(dev)) {
+ ret = dw_dp_runtime_resume(dp);
+ if (ret)
+ goto put_runtime_pm;
+ }
+
+ if (dp->plat_data.hpd_sw_sel)
+ dp->plat_data.hpd_sw_sel(dp->plat_data.data, dp->usbc_mode);
ret = phy_init(dp->phy);
if (ret) {
dev_err_probe(dev, ret, "phy init failed\n");
- goto put_next_bridge;
+ goto put_manual_pm;
}
enable_irq(dp->irq);
+ /*
+ * USB-C has out-of-band hotplug detection, so device may enter
+ * runtime suspend. Native mode needs to be resumed for working
+ * hotplug detection.
+ */
+ if (dp->usbc_mode) {
+ dev_dbg(dev, "USB-C mode\n");
+ pm_runtime_put_autosuspend(dp->dev);
+ }
+
return 0;
+put_manual_pm:
+ if (!pm_runtime_enabled(dev))
+ dw_dp_runtime_suspend(dp);
+
+put_runtime_pm:
+ pm_runtime_put_sync(dp->dev);
+
put_next_bridge:
drm_bridge_put(dp->next_bridge);
@@ -2101,6 +2152,11 @@ void dw_dp_unbind(struct dw_dp *dp)
disable_irq(dp->irq);
cancel_work_sync(&dp->hpd_work);
phy_exit(dp->phy);
+ if (!dp->usbc_mode)
+ pm_runtime_put_sync(dp->dev);
+ /* suspend once if runtime PM is disabled */
+ if (!pm_runtime_enabled(dp->dev))
+ dw_dp_runtime_suspend(dp);
drm_bridge_put(dp->next_bridge);
drm_dp_aux_unregister(&dp->aux);
drm_bridge_remove(&dp->bridge);
@@ -2149,13 +2205,13 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
return ERR_CAST(dp->phy);
}
- dp->apb_clk = devm_clk_get_enabled(dev, "apb");
+ dp->apb_clk = devm_clk_get(dev, "apb");
if (IS_ERR(dp->apb_clk)) {
dev_err_probe(dev, PTR_ERR(dp->apb_clk), "failed to get apb clock\n");
return ERR_CAST(dp->apb_clk);
}
- dp->aux_clk = devm_clk_get_enabled(dev, "aux");
+ dp->aux_clk = devm_clk_get(dev, "aux");
if (IS_ERR(dp->aux_clk)) {
dev_err_probe(dev, PTR_ERR(dp->aux_clk), "failed to get aux clock\n");
return ERR_CAST(dp->aux_clk);
@@ -2200,6 +2256,41 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
}
EXPORT_SYMBOL_GPL(dw_dp_probe);
+int dw_dp_runtime_suspend(struct dw_dp *dp)
+{
+ clk_disable_unprepare(dp->aux_clk);
+ clk_disable_unprepare(dp->apb_clk);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_suspend);
+
+int dw_dp_runtime_resume(struct dw_dp *dp)
+{
+ int ret;
+
+ ret = clk_prepare_enable(dp->apb_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(dp->aux_clk);
+ if (ret) {
+ clk_disable_unprepare(dp->apb_clk);
+ return ret;
+ }
+
+ dw_dp_init_hw(dp);
+
+ /*
+ * HPD_HOT_PLUG bit is asserted only after the sink holds HPD
+ * high for at least 100ms.
+ */
+ msleep(110);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_dp_runtime_resume);
+
MODULE_AUTHOR("Andy Yan <andyshrk@163.com>");
MODULE_DESCRIPTION("DW DP Core Library");
MODULE_LICENSE("GPL");
diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
index 79b2cdf0df99..f20d2c2c40ca 100644
--- a/include/drm/bridge/dw_dp.h
+++ b/include/drm/bridge/dw_dp.h
@@ -29,4 +29,7 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
void dw_dp_unbind(struct dw_dp *dp);
struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_data *plat_data);
+
+int dw_dp_runtime_suspend(struct dw_dp *dp);
+int dw_dp_runtime_resume(struct dw_dp *dp);
#endif /* __DW_DP__ */
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 11/16] drm/bridge: synopsys: dw-dp: Add Runtime PM support
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:24 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:24 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: dri-devel, conor+dt, devicetree, robh
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
New issues:
- [High] Using `guard(pm_runtime_noresume)` in the interrupt handler allows hardware access on a suspended device.
- [High] Unhandled failure of PM resume in `dw_dp_bridge_atomic_enable()` causes unbalanced PM operations and unclocked register accesses during teardown.
Pre-existing issues:
- [High] `drm_dp_aux_unregister()` is called too late in `dw_dp_unbind()`, allowing userspace to trigger AUX transfers on torn-down hardware.
--
--- Patch [11]: [PATCH v6 11/16] drm/bridge: synopsys: dw-dp: Add Runtime PM support ---
commit fb3ecb0112d9fff7c3a992e9273e0b7eaa8b8174
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/bridge: synopsys: dw-dp: Add Runtime PM support
Add runtime PM stubs to the Synopsys DesignWare DisplayPort bridge
driver. Support is not enabled automatically and must be hooked up
in the vendor specific glue code.
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
[ ... ]
> @@ -1659,6 +1665,12 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
> struct drm_connector_state *conn_state;
> int ret;
>
> + ret = pm_runtime_get_active(dp->dev, RPM_TRANSPARENT);
> + if (ret) {
> + dev_err(dp->dev, "runtime PM failure\n");
> + return;
> + }
> +
[Severity: High]
If acquiring the PM reference fails here, we log an error and return
early, but does the DRM core proceed as if the bridge is enabled?
Later, when tearing down the display pipeline,
dw_dp_bridge_atomic_disable() is called unconditionally. It executes
dw_dp_reset() (which accesses hardware registers) and
pm_runtime_put_autosuspend() (which drops a reference that was never
acquired). Could this lead to unclocked register accesses causing a bus
fault, and a PM usage counter underflow?
> connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
> if (!connector) {
> dev_err(dp->dev, "failed to get connector\n");
[ ... ]
> @@ -1966,6 +1988,9 @@ static irqreturn_t dw_dp_irq(int irq, void *data)
> struct dw_dp *dp = data;
> u32 value;
>
> + /* interrupt can only trigger for running device */
> + guard(pm_runtime_noresume)(dp->dev);
> +
> regmap_read(dp->regmap, DW_DP_GENERAL_INTERRUPT, &value);
[Severity: High]
Does using guard(pm_runtime_noresume) allow hardware access on a suspended
device?
Since dw_dp_runtime_suspend() disables clocks but does not disable the
IRQ, a shared interrupt or a glitch on the IRQ line while the device is
in runtime suspend could cause this handler to execute and read
DW_DP_GENERAL_INTERRUPT while clocks are off.
Should this use pm_runtime_get_if_active() instead to avoid a bus fault?
> if (!value)
> return IRQ_NONE;
[ ... ]
> @@ -2101,6 +2152,11 @@ void dw_dp_unbind(struct dw_dp *dp)
> disable_irq(dp->irq);
> cancel_work_sync(&dp->hpd_work);
> phy_exit(dp->phy);
> + if (!dp->usbc_mode)
> + pm_runtime_put_sync(dp->dev);
> + /* suspend once if runtime PM is disabled */
> + if (!pm_runtime_enabled(dp->dev))
> + dw_dp_runtime_suspend(dp);
> drm_bridge_put(dp->next_bridge);
> drm_dp_aux_unregister(&dp->aux);
[Severity: High]
This is a pre-existing issue, but is drm_dp_aux_unregister() called too
late here?
During device unbind, phy_exit() and disable_irq() are called before
drm_dp_aux_unregister(). Because the AUX device is still registered and
accessible to userspace, a userspace process could initiate an AUX
transfer that calls dw_dp_aux_transfer() while the PHY is uninitialized
and the IRQ is disabled, potentially causing a hardware fault or timeout.
> drm_bridge_remove(&dp->bridge);
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=11
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 12/16] drm/rockchip: dw_dp: Add runtime PM support
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Add support for runtime PM to the Rockchip RK3576/3588 Synopsys
DesignWare DisplayPort driver.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 50 ++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index ee0bd696064e..b8138e796c4d 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -12,6 +12,7 @@
#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/videodev2.h>
@@ -54,9 +55,15 @@ static void dw_dp_rockchip_hpd_sw_sel(void *data, bool force_hpd_from_sw)
{
struct rockchip_dw_dp *dp = data;
u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
dp->hpd_sel = force_hpd_from_sw;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
regmap_write(dp->vo_grf, hpd_reg,
FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel));
}
@@ -65,11 +72,17 @@ static void dw_dp_rockchip_hpd_sw_cfg(void *data, bool hpd)
{
struct rockchip_dw_dp *dp = data;
u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
dev_dbg(dp->dev, "Force HPD connected=%s\n", str_yes_no(hpd));
dp->hpd_cfg = hpd;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
regmap_write(dp->vo_grf, hpd_reg,
FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
}
@@ -200,7 +213,7 @@ static int dw_dp_rockchip_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct rockchip_dw_dp *dp;
struct resource *res;
- int id;
+ int id, ret;
plat_data_const = device_get_match_data(dev);
if (!plat_data_const)
@@ -247,6 +260,12 @@ static int dw_dp_rockchip_probe(struct platform_device *pdev)
if (IS_ERR(dp->base))
return PTR_ERR(dp->base);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_autosuspend_delay(dev, 500);
+ ret = devm_pm_runtime_enable(dev);
+ if (ret)
+ return ret;
+
return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
}
@@ -255,6 +274,34 @@ static void dw_dp_rockchip_remove(struct platform_device *pdev)
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
+static int dw_dp_rockchip_runtime_suspend(struct device *dev)
+{
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
+
+ return dw_dp_runtime_suspend(dp->base);
+}
+
+static int dw_dp_rockchip_runtime_resume(struct device *dev)
+{
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
+
+ ret = dw_dp_runtime_resume(dp->base);
+ if (ret)
+ return ret;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel) |
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
+
+ return 0;
+}
+
+static const struct dev_pm_ops dw_dp_pm_ops = {
+ RUNTIME_PM_OPS(dw_dp_rockchip_runtime_suspend, dw_dp_rockchip_runtime_resume, NULL)
+};
+
static const struct rockchip_dw_dp_plat_data rk3588_dp_plat_data = {
.num_ctrls = 2,
.ctrl_ids = {0xfde50000, 0xfde60000},
@@ -289,5 +336,6 @@ struct platform_driver dw_dp_driver = {
.driver = {
.name = "dw-dp",
.of_match_table = dw_dp_of_match,
+ .pm = pm_ptr(&dw_dp_pm_ops),
},
};
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 12/16] drm/rockchip: dw_dp: Add runtime PM support
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Add support for runtime PM to the Rockchip RK3576/3588 Synopsys
DesignWare DisplayPort driver.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 50 ++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
index ee0bd696064e..b8138e796c4d 100644
--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
@@ -12,6 +12,7 @@
#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/videodev2.h>
@@ -54,9 +55,15 @@ static void dw_dp_rockchip_hpd_sw_sel(void *data, bool force_hpd_from_sw)
{
struct rockchip_dw_dp *dp = data;
u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
dp->hpd_sel = force_hpd_from_sw;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
regmap_write(dp->vo_grf, hpd_reg,
FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel));
}
@@ -65,11 +72,17 @@ static void dw_dp_rockchip_hpd_sw_cfg(void *data, bool hpd)
{
struct rockchip_dw_dp *dp = data;
u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
dev_dbg(dp->dev, "Force HPD connected=%s\n", str_yes_no(hpd));
dp->hpd_cfg = hpd;
+ PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dp->dev, pm);
+ ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return;
+
regmap_write(dp->vo_grf, hpd_reg,
FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
}
@@ -200,7 +213,7 @@ static int dw_dp_rockchip_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct rockchip_dw_dp *dp;
struct resource *res;
- int id;
+ int id, ret;
plat_data_const = device_get_match_data(dev);
if (!plat_data_const)
@@ -247,6 +260,12 @@ static int dw_dp_rockchip_probe(struct platform_device *pdev)
if (IS_ERR(dp->base))
return PTR_ERR(dp->base);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_autosuspend_delay(dev, 500);
+ ret = devm_pm_runtime_enable(dev);
+ if (ret)
+ return ret;
+
return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
}
@@ -255,6 +274,34 @@ static void dw_dp_rockchip_remove(struct platform_device *pdev)
component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
}
+static int dw_dp_rockchip_runtime_suspend(struct device *dev)
+{
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
+
+ return dw_dp_runtime_suspend(dp->base);
+}
+
+static int dw_dp_rockchip_runtime_resume(struct device *dev)
+{
+ struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
+ u32 hpd_reg = dp->pdata->hpd_reg[dp->id];
+ int ret;
+
+ ret = dw_dp_runtime_resume(dp->base);
+ if (ret)
+ return ret;
+
+ regmap_write(dp->vo_grf, hpd_reg,
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_SEL, dp->hpd_sel) |
+ FIELD_PREP_WM16(ROCKCHIP_VO_GRF_DP_SINK_HPD_CFG, dp->hpd_cfg));
+
+ return 0;
+}
+
+static const struct dev_pm_ops dw_dp_pm_ops = {
+ RUNTIME_PM_OPS(dw_dp_rockchip_runtime_suspend, dw_dp_rockchip_runtime_resume, NULL)
+};
+
static const struct rockchip_dw_dp_plat_data rk3588_dp_plat_data = {
.num_ctrls = 2,
.ctrl_ids = {0xfde50000, 0xfde60000},
@@ -289,5 +336,6 @@ struct platform_driver dw_dp_driver = {
.driver = {
.name = "dw-dp",
.of_match_table = dw_dp_of_match,
+ .pm = pm_ptr(&dw_dp_pm_ops),
},
};
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 12/16] drm/rockchip: dw_dp: Add runtime PM support
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:27 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:27 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: devicetree, conor+dt, robh, dri-devel
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The DW DP core driver uses `guard(pm_runtime_noresume)` in its interrupt handler, allowing hardware register accesses while the device is suspended and its clocks are disabled.
--
--- Patch [12]: [PATCH v6 12/16] drm/rockchip: dw_dp: Add runtime PM support ---
commit 76fb970e196b210c9742e601b51113d5f65dd02f
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/rockchip: dw_dp: Add runtime PM support
This commit adds support for runtime PM to the Rockchip RK3576/3588 Synopsys
DesignWare DisplayPort driver.
> diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
> index ee0bd696064eb..b8138e796c4d5 100644
> --- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
[ ... ]
> @@ -247,6 +260,12 @@ static int dw_dp_rockchip_probe(struct platform_device *pdev)
> if (IS_ERR(dp->base))
> return PTR_ERR(dp->base);
>
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_set_autosuspend_delay(dev, 500);
> + ret = devm_pm_runtime_enable(dev);
[Severity: High]
Does enabling runtime PM here expose a bus fault in the core dw_dp_irq
handler on suspended devices?
The core DW DP driver uses guard(pm_runtime_noresume) which only increments
the PM usage counter without checking the actual power state:
drivers/gpu/drm/bridge/synopsys/dw-dp.c:dw_dp_irq() {
/* interrupt can only trigger for running device */
guard(pm_runtime_noresume)(dp->dev);
regmap_read(dp->regmap, DW_DP_GENERAL_INTERRUPT, &value);
...
}
If a spurious or delayed interrupt fires while the DP controller is
suspended and its clocks are disabled, this allows the handler to execute
and read from DW_DP_GENERAL_INTERRUPT.
Accessing memory-mapped registers over a disabled APB bus can cause a bus
fault (such as an SError on ARM) resulting in a kernel panic.
Should the core driver be updated to use pm_runtime_get_if_active()
to safely verify the device is active before accessing hardware registers?
> + if (ret)
> + return ret;
> +
> return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=12
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v6 13/16] drm/bridge: synopsys: dw-dp: Protect sdp_reg_bank from concurrent access
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Right now sdp_reg_bank is only used during atomic enable/disable and
thus there is no risk of two threads accidently claiming the same bit.
This changes once more SDP users (like audio support) are added, so
introduce a mutex to protect concurrent access to the bitmap.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 1bbb39b8d0be..88b95938649a 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -322,6 +322,8 @@ struct dw_dp {
struct dw_dp_hotplug hotplug;
/* Serialize hpd status access */
struct mutex irq_lock;
+ /* Serialize sdp_reg_bank access */
+ struct mutex sdp_lock;
struct drm_dp_aux aux;
@@ -1045,11 +1047,13 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
u32 reg;
int i, nr;
- nr = find_first_zero_bit(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
- if (nr < SDP_REG_BANK_SIZE)
- set_bit(nr, dp->sdp_reg_bank);
- else
- return -EBUSY;
+ scoped_guard(mutex, &dp->sdp_lock) {
+ nr = find_first_zero_bit(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+ if (nr < SDP_REG_BANK_SIZE)
+ set_bit(nr, dp->sdp_reg_bank);
+ else
+ return -EBUSY;
+ }
reg = DW_DP_SDP_REGISTER_BANK + nr * 9 * 4;
@@ -1683,7 +1687,8 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
return;
}
- set_bit(0, dp->sdp_reg_bank);
+ scoped_guard(mutex, &dp->sdp_lock)
+ set_bit(0, dp->sdp_reg_bank);
ret = dw_dp_link_enable(dp);
if (ret < 0) {
@@ -1723,7 +1728,8 @@ static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
dw_dp_video_disable(dp);
dw_dp_link_disable(dp);
- bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+ scoped_guard(mutex, &dp->sdp_lock)
+ bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
dw_dp_reset(dp);
pm_runtime_put_autosuspend(dp->dev);
}
@@ -2189,6 +2195,10 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
if (ret)
return ERR_PTR(ret);
+ ret = devm_mutex_init(dev, &dp->sdp_lock);
+ if (ret)
+ return ERR_PTR(ret);
+
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res))
return ERR_CAST(res);
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 13/16] drm/bridge: synopsys: dw-dp: Protect sdp_reg_bank from concurrent access
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Right now sdp_reg_bank is only used during atomic enable/disable and
thus there is no risk of two threads accidently claiming the same bit.
This changes once more SDP users (like audio support) are added, so
introduce a mutex to protect concurrent access to the bitmap.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 1bbb39b8d0be..88b95938649a 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -322,6 +322,8 @@ struct dw_dp {
struct dw_dp_hotplug hotplug;
/* Serialize hpd status access */
struct mutex irq_lock;
+ /* Serialize sdp_reg_bank access */
+ struct mutex sdp_lock;
struct drm_dp_aux aux;
@@ -1045,11 +1047,13 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
u32 reg;
int i, nr;
- nr = find_first_zero_bit(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
- if (nr < SDP_REG_BANK_SIZE)
- set_bit(nr, dp->sdp_reg_bank);
- else
- return -EBUSY;
+ scoped_guard(mutex, &dp->sdp_lock) {
+ nr = find_first_zero_bit(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+ if (nr < SDP_REG_BANK_SIZE)
+ set_bit(nr, dp->sdp_reg_bank);
+ else
+ return -EBUSY;
+ }
reg = DW_DP_SDP_REGISTER_BANK + nr * 9 * 4;
@@ -1683,7 +1687,8 @@ static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
return;
}
- set_bit(0, dp->sdp_reg_bank);
+ scoped_guard(mutex, &dp->sdp_lock)
+ set_bit(0, dp->sdp_reg_bank);
ret = dw_dp_link_enable(dp);
if (ret < 0) {
@@ -1723,7 +1728,8 @@ static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
dw_dp_video_disable(dp);
dw_dp_link_disable(dp);
- bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+ scoped_guard(mutex, &dp->sdp_lock)
+ bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
dw_dp_reset(dp);
pm_runtime_put_autosuspend(dp->dev);
}
@@ -2189,6 +2195,10 @@ struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct dw_dp_plat_
if (ret)
return ERR_PTR(ret);
+ ret = devm_mutex_init(dev, &dp->sdp_lock);
+ if (ret)
+ return ERR_PTR(ret);
+
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res))
return ERR_CAST(res);
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 14/16] drm/bridge: synopsys: dw-dp: Use regmap_set_bits in dw_dp_send_sdp
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Simplify dw_dp_send_sdp() a little bit by making use of
regmap_set_bits.
No functional change intended.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 88b95938649a..44a13b5d62d3 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1066,14 +1066,12 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
FIELD_PREP(SDP_REGS, get_unaligned_le32(payload)));
if (sdp->flags & DW_DP_SDP_VERTICAL_INTERVAL)
- regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
- EN_VERTICAL_SDP << nr,
- EN_VERTICAL_SDP << nr);
+ regmap_set_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_VERTICAL_SDP << nr);
if (sdp->flags & DW_DP_SDP_HORIZONTAL_INTERVAL)
- regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
- EN_HORIZONTAL_SDP << nr,
- EN_HORIZONTAL_SDP << nr);
+ regmap_set_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_HORIZONTAL_SDP << nr);
return 0;
}
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 14/16] drm/bridge: synopsys: dw-dp: Use regmap_set_bits in dw_dp_send_sdp
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Simplify dw_dp_send_sdp() a little bit by making use of
regmap_set_bits.
No functional change intended.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 88b95938649a..44a13b5d62d3 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1066,14 +1066,12 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
FIELD_PREP(SDP_REGS, get_unaligned_le32(payload)));
if (sdp->flags & DW_DP_SDP_VERTICAL_INTERVAL)
- regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
- EN_VERTICAL_SDP << nr,
- EN_VERTICAL_SDP << nr);
+ regmap_set_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_VERTICAL_SDP << nr);
if (sdp->flags & DW_DP_SDP_HORIZONTAL_INTERVAL)
- regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
- EN_HORIZONTAL_SDP << nr,
- EN_HORIZONTAL_SDP << nr);
+ regmap_set_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_HORIZONTAL_SDP << nr);
return 0;
}
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 15/16] dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
The RK3588 and RK3576 DesignWare DisplayPort controllers both have two
possible DAI interfaces: I2S and S/PDIF. Thus an argument is needed to
to select the right interface.
In addition to that the RK3576 DisplayPort controller is configured
with Multi Stream Transport (MST) enabled for up to 3 displays and
thus has a total of 6 DAI interfaces (I2S and S/PDIF for each possible
stream). Meanwhile the RK3588 does not support MST and thus has only 2
DAI interfaces.
The binding update from this patch has only been tested with the simple
single stream transport (SST) setup as the Linux driver does not yet
support MST. Once MST support is added, the plan is to simply add more
numbers to the argument, so that it looks like this for RK3576:
0 = I2S on stream 0,
1 = S/PDIF on stream 0
2 = I2S on stream 1,
3 = S/PDIF on stream 1
4 = I2S on stream 2,
5 = S/PDIF on stream 2
As the arguments are not part of the binding itself the audio side
is also ready for MST after this change.
Switching '#sound-dai-cells' from 0 to 1 without keeping compatibility
is an ABI break. The rationale for going that way is, that there is not
a single known driver implementation for the current binding. It's also
unclear how the current binding would be used (only support I2S or
S/PDIF for stream 0?). The mainline rk3588 DTS include sets it to 0, but
does not have any soundcard using the DAI. This will be fixed up
separately. The RK3576 does not set it at all.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
.../devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
index 2b0d9e23e943..c4f8959dd65d 100644
--- a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
+++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
@@ -25,7 +25,7 @@ description: |
* Supports up to 8/10 bits per color component
* Supports RBG, YCbCr4:4:4, YCbCr4:2:2, YCbCr4:2:0
* Pixel clock up to 594MHz
- * I2S, SPDIF audio interface
+ * I2S, S/PDIF audio interface
properties:
compatible:
@@ -46,7 +46,7 @@ properties:
- description: DisplayPort AUX clock
- description: HDCP clock
- description: I2S interface clock
- - description: SPDIF interfce clock
+ - description: S/PDIF interfce clock
clock-names:
minItems: 3
@@ -83,7 +83,8 @@ properties:
maxItems: 1
"#sound-dai-cells":
- const: 0
+ const: 1
+ description: 0 for I2S, 1 for S/PDIF
required:
- compatible
@@ -144,7 +145,7 @@ examples:
resets = <&cru SRST_DP0>;
phys = <&usbdp_phy0 PHY_TYPE_DP>;
power-domains = <&power RK3588_PD_VO0>;
- #sound-dai-cells = <0>;
+ #sound-dai-cells = <1>;
ports {
#address-cells = <1>;
--
2.53.0
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 15/16] dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
The RK3588 and RK3576 DesignWare DisplayPort controllers both have two
possible DAI interfaces: I2S and S/PDIF. Thus an argument is needed to
to select the right interface.
In addition to that the RK3576 DisplayPort controller is configured
with Multi Stream Transport (MST) enabled for up to 3 displays and
thus has a total of 6 DAI interfaces (I2S and S/PDIF for each possible
stream). Meanwhile the RK3588 does not support MST and thus has only 2
DAI interfaces.
The binding update from this patch has only been tested with the simple
single stream transport (SST) setup as the Linux driver does not yet
support MST. Once MST support is added, the plan is to simply add more
numbers to the argument, so that it looks like this for RK3576:
0 = I2S on stream 0,
1 = S/PDIF on stream 0
2 = I2S on stream 1,
3 = S/PDIF on stream 1
4 = I2S on stream 2,
5 = S/PDIF on stream 2
As the arguments are not part of the binding itself the audio side
is also ready for MST after this change.
Switching '#sound-dai-cells' from 0 to 1 without keeping compatibility
is an ABI break. The rationale for going that way is, that there is not
a single known driver implementation for the current binding. It's also
unclear how the current binding would be used (only support I2S or
S/PDIF for stream 0?). The mainline rk3588 DTS include sets it to 0, but
does not have any soundcard using the DAI. This will be fixed up
separately. The RK3576 does not set it at all.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
.../devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
index 2b0d9e23e943..c4f8959dd65d 100644
--- a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
+++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
@@ -25,7 +25,7 @@ description: |
* Supports up to 8/10 bits per color component
* Supports RBG, YCbCr4:4:4, YCbCr4:2:2, YCbCr4:2:0
* Pixel clock up to 594MHz
- * I2S, SPDIF audio interface
+ * I2S, S/PDIF audio interface
properties:
compatible:
@@ -46,7 +46,7 @@ properties:
- description: DisplayPort AUX clock
- description: HDCP clock
- description: I2S interface clock
- - description: SPDIF interfce clock
+ - description: S/PDIF interfce clock
clock-names:
minItems: 3
@@ -83,7 +83,8 @@ properties:
maxItems: 1
"#sound-dai-cells":
- const: 0
+ const: 1
+ description: 0 for I2S, 1 for S/PDIF
required:
- compatible
@@ -144,7 +145,7 @@ examples:
resets = <&cru SRST_DP0>;
phys = <&usbdp_phy0 PHY_TYPE_DP>;
power-domains = <&power RK3588_PD_VO0>;
- #sound-dai-cells = <0>;
+ #sound-dai-cells = <1>;
ports {
#address-cells = <1>;
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v6 16/16] drm/bridge: synopsys: dw-dp: Add audio support
2026-07-24 18:03 ` Sebastian Reichel
@ 2026-07-24 18:03 ` Sebastian Reichel
-1 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: devicetree, Dmitry Baryshkov, linux-kernel, dri-devel,
Sebastian Reichel, Alexey Charkov, linux-rockchip, Damon Ding,
kernel, linux-arm-kernel
Implement audio support for the Synopsys DesignWare DisplayPort
controller.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 263 +++++++++++++++++++++++++++++++-
1 file changed, 261 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 44a13b5d62d3..c7d6f63b5e9a 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -23,17 +23,21 @@
#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/display/drm_dp_helper.h>
+#include <drm/display/drm_hdmi_audio_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
+#include <sound/hdmi-codec.h>
+
#define DW_DP_VERSION_NUMBER 0x0000
#define DW_DP_VERSION_TYPE 0x0004
#define DW_DP_ID 0x0008
#define DW_DP_CONFIG_REG1 0x0100
+#define AUDIO_SELECT GENMASK(2, 1)
#define DW_DP_CONFIG_REG2 0x0104
#define DW_DP_CONFIG_REG3 0x0108
@@ -110,6 +114,10 @@
#define HBR_MODE_ENABLE BIT(10)
#define AUDIO_DATA_WIDTH GENMASK(9, 5)
#define AUDIO_DATA_IN_EN GENMASK(4, 1)
+#define AUDIO_DATA_IN_EN_CHANNEL12 BIT(0)
+#define AUDIO_DATA_IN_EN_CHANNEL34 BIT(1)
+#define AUDIO_DATA_IN_EN_CHANNEL56 BIT(2)
+#define AUDIO_DATA_IN_EN_CHANNEL78 BIT(3)
#define AUDIO_INF_SELECT BIT(0)
#define DW_DP_SDP_VERTICAL_CTRL 0x0500
@@ -253,6 +261,8 @@
#define SDP_REG_BANK_SIZE 16
+#define DW_DP_SDP_VERSION 0x12
+
struct dw_dp_link_caps {
bool enhanced_framing;
bool tps3_supported;
@@ -305,6 +315,19 @@ struct dw_dp_hotplug {
bool long_hpd;
};
+enum dw_dp_audio_interface_support {
+ DW_DP_AUDIO_I2S_ONLY = 0,
+ DW_DP_AUDIO_SPDIF_ONLY = 1,
+ DW_DP_AUDIO_I2S_AND_SPDIF = 2,
+ DW_DP_AUDIO_NONE = 3,
+};
+
+enum dw_dp_audio_interface {
+ DW_DP_AUDIO_I2S = 0,
+ DW_DP_AUDIO_SPDIF = 1,
+ DW_DP_AUDIO_UNUSED,
+};
+
struct dw_dp {
struct drm_bridge bridge;
struct device *dev;
@@ -320,6 +343,9 @@ struct dw_dp {
int irq;
struct work_struct hpd_work;
struct dw_dp_hotplug hotplug;
+ enum dw_dp_audio_interface audio_interface;
+ int audio_channels;
+ int audio_sdp_nr;
/* Serialize hpd status access */
struct mutex irq_lock;
/* Serialize sdp_reg_bank access */
@@ -1073,7 +1099,19 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
regmap_set_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
EN_HORIZONTAL_SDP << nr);
- return 0;
+ return nr;
+}
+
+static void dw_dp_clear_sdp(struct dw_dp *dp, int nr)
+{
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_VERTICAL_SDP << nr);
+
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_HORIZONTAL_SDP << nr);
+
+ scoped_guard(mutex, &dp->sdp_lock)
+ clear_bit(nr, dp->sdp_reg_bank);
}
static int dw_dp_send_vsc_sdp(struct dw_dp *dp)
@@ -1886,6 +1924,212 @@ static void dw_dp_bridge_oob_notify(struct drm_bridge *bridge,
dev_err_once(dp->dev, "Missing platform handler for OOB HPD handling\n");
}
+static int dw_dp_audio_infoframe_send(struct dw_dp *dp)
+{
+ struct hdmi_audio_infoframe frame;
+ struct dw_dp_sdp sdp;
+ int ret;
+
+ ret = hdmi_audio_infoframe_init(&frame);
+ if (ret < 0)
+ return ret;
+
+ frame.coding_type = HDMI_AUDIO_CODING_TYPE_STREAM;
+ frame.sample_frequency = HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM;
+ frame.sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
+ frame.channels = dp->audio_channels;
+
+ ret = hdmi_audio_infoframe_pack_for_dp(&frame, &sdp.base, DW_DP_SDP_VERSION);
+ if (ret < 0)
+ return ret;
+
+ sdp.flags = DW_DP_SDP_VERTICAL_INTERVAL;
+
+ return dw_dp_send_sdp(dp, &sdp);
+}
+
+static int dw_dp_audio_startup(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio startup\n");
+
+ return pm_runtime_resume_and_get(dp->dev);
+}
+
+static void dw_dp_audio_unprepare(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ if (dp->audio_sdp_nr >= 0) {
+ dw_dp_clear_sdp(dp, dp->audio_sdp_nr);
+ dp->audio_sdp_nr = -1;
+ }
+
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_AUDIO_STREAM_SDP | EN_AUDIO_TIMESTAMP_SDP);
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_AUDIO_STREAM_SDP);
+
+ regmap_clear_bits(dp->regmap, DW_DP_AUD_CONFIG1, AUDIO_DATA_IN_EN);
+
+ if (dp->audio_interface == DW_DP_AUDIO_SPDIF)
+ clk_disable_unprepare(dp->spdif_clk);
+ else if (dp->audio_interface == DW_DP_AUDIO_I2S)
+ clk_disable_unprepare(dp->i2s_clk);
+
+ dp->audio_interface = DW_DP_AUDIO_UNUSED;
+}
+
+static int dw_dp_audio_prepare(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ struct hdmi_codec_daifmt *daifmt,
+ struct hdmi_codec_params *params)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+ u8 audio_data_in_en, supported_audio_interfaces;
+ enum dw_dp_audio_interface audio_interface;
+ u32 cfg1;
+ int ret;
+
+ /*
+ * prepare might be called multiple times, so release the clocks
+ * from previous calls to keep the calls in balance.
+ */
+ if (dp->audio_interface != DW_DP_AUDIO_UNUSED)
+ dw_dp_audio_unprepare(bridge, connector);
+
+ /* The hardware is limited to 1,2 or 8 channels */
+ dp->audio_channels = params->cea.channels;
+ switch (params->cea.channels) {
+ case 1:
+ case 2:
+ audio_data_in_en = AUDIO_DATA_IN_EN_CHANNEL12;
+ break;
+ case 8:
+ audio_data_in_en = AUDIO_DATA_IN_EN_CHANNEL12 |
+ AUDIO_DATA_IN_EN_CHANNEL34 |
+ AUDIO_DATA_IN_EN_CHANNEL56 |
+ AUDIO_DATA_IN_EN_CHANNEL78;
+ break;
+ default:
+ dev_err(dp->dev, "invalid audio channels %d\n", dp->audio_channels);
+ return -EINVAL;
+ }
+
+ if (params->sample_width < 16 || params->sample_width > 24) {
+ dev_err(dp->dev, "invalid data sample width %d\n", params->sample_width);
+ return -EINVAL;
+ }
+
+ switch (daifmt->fmt) {
+ case HDMI_SPDIF:
+ audio_interface = DW_DP_AUDIO_SPDIF;
+ break;
+ case HDMI_I2S:
+ /*
+ * It is recommended to use SPDIF instead of I2S, since I2S mode requires
+ * manually inserting PCUV control bits from userspace and this is done
+ * automatically in hardware for SPDIF mode.
+ */
+ audio_interface = DW_DP_AUDIO_I2S;
+ break;
+ default:
+ dev_err(dp->dev, "invalid DAI format %d\n", daifmt->fmt);
+ return -EINVAL;
+ }
+
+ regmap_read(dp->regmap, DW_DP_CONFIG_REG1, &cfg1);
+ supported_audio_interfaces = FIELD_GET(AUDIO_SELECT, cfg1);
+
+ if (supported_audio_interfaces != DW_DP_AUDIO_I2S_AND_SPDIF &&
+ supported_audio_interfaces != audio_interface) {
+ dev_err(dp->dev, "unsupported DAI %d\n", daifmt->fmt);
+ return -EINVAL;
+ }
+
+ ret = clk_prepare_enable(dp->spdif_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(dp->i2s_clk);
+ if (ret) {
+ clk_disable_unprepare(dp->spdif_clk);
+ return ret;
+ }
+
+ regmap_update_bits(dp->regmap, DW_DP_AUD_CONFIG1,
+ AUDIO_DATA_IN_EN | NUM_CHANNELS | AUDIO_DATA_WIDTH |
+ AUDIO_INF_SELECT | HBR_MODE_ENABLE,
+ FIELD_PREP(AUDIO_DATA_IN_EN, audio_data_in_en) |
+ FIELD_PREP(NUM_CHANNELS, dp->audio_channels - 1) |
+ FIELD_PREP(AUDIO_DATA_WIDTH, params->sample_width) |
+ FIELD_PREP(AUDIO_INF_SELECT, audio_interface) |
+ FIELD_PREP(HBR_MODE_ENABLE, 0));
+
+ /* Wait for inf switch */
+ usleep_range(20, 40);
+
+ if (audio_interface == DW_DP_AUDIO_I2S)
+ clk_disable_unprepare(dp->spdif_clk);
+ else if (audio_interface == DW_DP_AUDIO_SPDIF)
+ clk_disable_unprepare(dp->i2s_clk);
+
+ dp->audio_interface = audio_interface;
+
+ /*
+ * Send audio stream during vertical and horizontal blanking periods.
+ * Send out audio timestamp SDP once per video frame during the vertical
+ * blanking period
+ */
+ regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_AUDIO_STREAM_SDP | EN_AUDIO_TIMESTAMP_SDP,
+ FIELD_PREP(EN_AUDIO_STREAM_SDP, 1) |
+ FIELD_PREP(EN_AUDIO_TIMESTAMP_SDP, 1));
+ regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_AUDIO_STREAM_SDP,
+ FIELD_PREP(EN_AUDIO_STREAM_SDP, 1));
+
+ dp->audio_sdp_nr = dw_dp_audio_infoframe_send(dp);
+ if (dp->audio_sdp_nr < 0) {
+ dev_err(dp->dev, "failed to send audio infoframe\n");
+ dw_dp_audio_unprepare(bridge, connector);
+ return dp->audio_sdp_nr;
+ }
+
+ dev_dbg(dp->dev, "audio prepare with %d channels using DAI=%d\n",
+ dp->audio_channels, dp->audio_interface);
+
+ return 0;
+}
+
+static void dw_dp_audio_shutdown(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio shutdown\n");
+
+ dw_dp_audio_unprepare(bridge, connector);
+ pm_runtime_put_autosuspend(dp->dev);
+}
+
+static int dw_dp_audio_mute_stream(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ bool enable, int direction)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio %smute\n", enable ? "" : "un");
+
+ regmap_update_bits(dp->regmap, DW_DP_AUD_CONFIG1, AUDIO_MUTE,
+ FIELD_PREP(AUDIO_MUTE, enable));
+
+ return 0;
+}
+
static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
@@ -1899,6 +2143,11 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.detect = dw_dp_bridge_detect,
.edid_read = dw_dp_bridge_edid_read,
.oob_notify = dw_dp_bridge_oob_notify,
+
+ .dp_audio_startup = dw_dp_audio_startup,
+ .dp_audio_prepare = dw_dp_audio_prepare,
+ .dp_audio_shutdown = dw_dp_audio_shutdown,
+ .dp_audio_mute_stream = dw_dp_audio_mute_stream,
};
static int dw_dp_link_retrain(struct dw_dp *dp)
@@ -2057,10 +2306,20 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
bridge = &dp->bridge;
bridge->of_node = dev->of_node;
- bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+ bridge->ops = DRM_BRIDGE_OP_DP_AUDIO |
+ DRM_BRIDGE_OP_DETECT |
+ DRM_BRIDGE_OP_EDID |
+ DRM_BRIDGE_OP_HPD;
bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
bridge->ycbcr_420_allowed = true;
+ dp->audio_interface = DW_DP_AUDIO_UNUSED;
+ dp->audio_sdp_nr = -1;
+ bridge->hdmi_audio_dev = dev;
+ bridge->hdmi_audio_max_i2s_playback_channels = 8;
+ bridge->hdmi_audio_dai_port = 1;
+ bridge->hdmi_audio_spdif_playback = true;
+
drm_bridge_add(bridge);
dp->aux.dev = dev;
--
2.53.0
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^ permalink raw reply related [flat|nested] 41+ messages in thread* [PATCH v6 16/16] drm/bridge: synopsys: dw-dp: Add audio support
@ 2026-07-24 18:03 ` Sebastian Reichel
0 siblings, 0 replies; 41+ messages in thread
From: Sebastian Reichel @ 2026-07-24 18:03 UTC (permalink / raw)
To: Sandy Huang, Heiko Stübner, Andy Yan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong,
Robert Foss, Laurent Pinchart, Jonas Karlman, Jernej Skrabec,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, David Airlie,
Simona Vetter, Dmitry Baryshkov, Luca Ceresoli
Cc: Cristian Ciocaltea, Damon Ding, Dmitry Baryshkov, Alexey Charkov,
dri-devel, linux-rockchip, linux-kernel, devicetree, kernel,
linux-arm-kernel, Sebastian Reichel
Implement audio support for the Synopsys DesignWare DisplayPort
controller.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 263 +++++++++++++++++++++++++++++++-
1 file changed, 261 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 44a13b5d62d3..c7d6f63b5e9a 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -23,17 +23,21 @@
#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/display/drm_dp_helper.h>
+#include <drm/display/drm_hdmi_audio_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
+#include <sound/hdmi-codec.h>
+
#define DW_DP_VERSION_NUMBER 0x0000
#define DW_DP_VERSION_TYPE 0x0004
#define DW_DP_ID 0x0008
#define DW_DP_CONFIG_REG1 0x0100
+#define AUDIO_SELECT GENMASK(2, 1)
#define DW_DP_CONFIG_REG2 0x0104
#define DW_DP_CONFIG_REG3 0x0108
@@ -110,6 +114,10 @@
#define HBR_MODE_ENABLE BIT(10)
#define AUDIO_DATA_WIDTH GENMASK(9, 5)
#define AUDIO_DATA_IN_EN GENMASK(4, 1)
+#define AUDIO_DATA_IN_EN_CHANNEL12 BIT(0)
+#define AUDIO_DATA_IN_EN_CHANNEL34 BIT(1)
+#define AUDIO_DATA_IN_EN_CHANNEL56 BIT(2)
+#define AUDIO_DATA_IN_EN_CHANNEL78 BIT(3)
#define AUDIO_INF_SELECT BIT(0)
#define DW_DP_SDP_VERTICAL_CTRL 0x0500
@@ -253,6 +261,8 @@
#define SDP_REG_BANK_SIZE 16
+#define DW_DP_SDP_VERSION 0x12
+
struct dw_dp_link_caps {
bool enhanced_framing;
bool tps3_supported;
@@ -305,6 +315,19 @@ struct dw_dp_hotplug {
bool long_hpd;
};
+enum dw_dp_audio_interface_support {
+ DW_DP_AUDIO_I2S_ONLY = 0,
+ DW_DP_AUDIO_SPDIF_ONLY = 1,
+ DW_DP_AUDIO_I2S_AND_SPDIF = 2,
+ DW_DP_AUDIO_NONE = 3,
+};
+
+enum dw_dp_audio_interface {
+ DW_DP_AUDIO_I2S = 0,
+ DW_DP_AUDIO_SPDIF = 1,
+ DW_DP_AUDIO_UNUSED,
+};
+
struct dw_dp {
struct drm_bridge bridge;
struct device *dev;
@@ -320,6 +343,9 @@ struct dw_dp {
int irq;
struct work_struct hpd_work;
struct dw_dp_hotplug hotplug;
+ enum dw_dp_audio_interface audio_interface;
+ int audio_channels;
+ int audio_sdp_nr;
/* Serialize hpd status access */
struct mutex irq_lock;
/* Serialize sdp_reg_bank access */
@@ -1073,7 +1099,19 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
regmap_set_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
EN_HORIZONTAL_SDP << nr);
- return 0;
+ return nr;
+}
+
+static void dw_dp_clear_sdp(struct dw_dp *dp, int nr)
+{
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_VERTICAL_SDP << nr);
+
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_HORIZONTAL_SDP << nr);
+
+ scoped_guard(mutex, &dp->sdp_lock)
+ clear_bit(nr, dp->sdp_reg_bank);
}
static int dw_dp_send_vsc_sdp(struct dw_dp *dp)
@@ -1886,6 +1924,212 @@ static void dw_dp_bridge_oob_notify(struct drm_bridge *bridge,
dev_err_once(dp->dev, "Missing platform handler for OOB HPD handling\n");
}
+static int dw_dp_audio_infoframe_send(struct dw_dp *dp)
+{
+ struct hdmi_audio_infoframe frame;
+ struct dw_dp_sdp sdp;
+ int ret;
+
+ ret = hdmi_audio_infoframe_init(&frame);
+ if (ret < 0)
+ return ret;
+
+ frame.coding_type = HDMI_AUDIO_CODING_TYPE_STREAM;
+ frame.sample_frequency = HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM;
+ frame.sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
+ frame.channels = dp->audio_channels;
+
+ ret = hdmi_audio_infoframe_pack_for_dp(&frame, &sdp.base, DW_DP_SDP_VERSION);
+ if (ret < 0)
+ return ret;
+
+ sdp.flags = DW_DP_SDP_VERTICAL_INTERVAL;
+
+ return dw_dp_send_sdp(dp, &sdp);
+}
+
+static int dw_dp_audio_startup(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio startup\n");
+
+ return pm_runtime_resume_and_get(dp->dev);
+}
+
+static void dw_dp_audio_unprepare(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ if (dp->audio_sdp_nr >= 0) {
+ dw_dp_clear_sdp(dp, dp->audio_sdp_nr);
+ dp->audio_sdp_nr = -1;
+ }
+
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_AUDIO_STREAM_SDP | EN_AUDIO_TIMESTAMP_SDP);
+ regmap_clear_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_AUDIO_STREAM_SDP);
+
+ regmap_clear_bits(dp->regmap, DW_DP_AUD_CONFIG1, AUDIO_DATA_IN_EN);
+
+ if (dp->audio_interface == DW_DP_AUDIO_SPDIF)
+ clk_disable_unprepare(dp->spdif_clk);
+ else if (dp->audio_interface == DW_DP_AUDIO_I2S)
+ clk_disable_unprepare(dp->i2s_clk);
+
+ dp->audio_interface = DW_DP_AUDIO_UNUSED;
+}
+
+static int dw_dp_audio_prepare(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ struct hdmi_codec_daifmt *daifmt,
+ struct hdmi_codec_params *params)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+ u8 audio_data_in_en, supported_audio_interfaces;
+ enum dw_dp_audio_interface audio_interface;
+ u32 cfg1;
+ int ret;
+
+ /*
+ * prepare might be called multiple times, so release the clocks
+ * from previous calls to keep the calls in balance.
+ */
+ if (dp->audio_interface != DW_DP_AUDIO_UNUSED)
+ dw_dp_audio_unprepare(bridge, connector);
+
+ /* The hardware is limited to 1,2 or 8 channels */
+ dp->audio_channels = params->cea.channels;
+ switch (params->cea.channels) {
+ case 1:
+ case 2:
+ audio_data_in_en = AUDIO_DATA_IN_EN_CHANNEL12;
+ break;
+ case 8:
+ audio_data_in_en = AUDIO_DATA_IN_EN_CHANNEL12 |
+ AUDIO_DATA_IN_EN_CHANNEL34 |
+ AUDIO_DATA_IN_EN_CHANNEL56 |
+ AUDIO_DATA_IN_EN_CHANNEL78;
+ break;
+ default:
+ dev_err(dp->dev, "invalid audio channels %d\n", dp->audio_channels);
+ return -EINVAL;
+ }
+
+ if (params->sample_width < 16 || params->sample_width > 24) {
+ dev_err(dp->dev, "invalid data sample width %d\n", params->sample_width);
+ return -EINVAL;
+ }
+
+ switch (daifmt->fmt) {
+ case HDMI_SPDIF:
+ audio_interface = DW_DP_AUDIO_SPDIF;
+ break;
+ case HDMI_I2S:
+ /*
+ * It is recommended to use SPDIF instead of I2S, since I2S mode requires
+ * manually inserting PCUV control bits from userspace and this is done
+ * automatically in hardware for SPDIF mode.
+ */
+ audio_interface = DW_DP_AUDIO_I2S;
+ break;
+ default:
+ dev_err(dp->dev, "invalid DAI format %d\n", daifmt->fmt);
+ return -EINVAL;
+ }
+
+ regmap_read(dp->regmap, DW_DP_CONFIG_REG1, &cfg1);
+ supported_audio_interfaces = FIELD_GET(AUDIO_SELECT, cfg1);
+
+ if (supported_audio_interfaces != DW_DP_AUDIO_I2S_AND_SPDIF &&
+ supported_audio_interfaces != audio_interface) {
+ dev_err(dp->dev, "unsupported DAI %d\n", daifmt->fmt);
+ return -EINVAL;
+ }
+
+ ret = clk_prepare_enable(dp->spdif_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(dp->i2s_clk);
+ if (ret) {
+ clk_disable_unprepare(dp->spdif_clk);
+ return ret;
+ }
+
+ regmap_update_bits(dp->regmap, DW_DP_AUD_CONFIG1,
+ AUDIO_DATA_IN_EN | NUM_CHANNELS | AUDIO_DATA_WIDTH |
+ AUDIO_INF_SELECT | HBR_MODE_ENABLE,
+ FIELD_PREP(AUDIO_DATA_IN_EN, audio_data_in_en) |
+ FIELD_PREP(NUM_CHANNELS, dp->audio_channels - 1) |
+ FIELD_PREP(AUDIO_DATA_WIDTH, params->sample_width) |
+ FIELD_PREP(AUDIO_INF_SELECT, audio_interface) |
+ FIELD_PREP(HBR_MODE_ENABLE, 0));
+
+ /* Wait for inf switch */
+ usleep_range(20, 40);
+
+ if (audio_interface == DW_DP_AUDIO_I2S)
+ clk_disable_unprepare(dp->spdif_clk);
+ else if (audio_interface == DW_DP_AUDIO_SPDIF)
+ clk_disable_unprepare(dp->i2s_clk);
+
+ dp->audio_interface = audio_interface;
+
+ /*
+ * Send audio stream during vertical and horizontal blanking periods.
+ * Send out audio timestamp SDP once per video frame during the vertical
+ * blanking period
+ */
+ regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+ EN_AUDIO_STREAM_SDP | EN_AUDIO_TIMESTAMP_SDP,
+ FIELD_PREP(EN_AUDIO_STREAM_SDP, 1) |
+ FIELD_PREP(EN_AUDIO_TIMESTAMP_SDP, 1));
+ regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+ EN_AUDIO_STREAM_SDP,
+ FIELD_PREP(EN_AUDIO_STREAM_SDP, 1));
+
+ dp->audio_sdp_nr = dw_dp_audio_infoframe_send(dp);
+ if (dp->audio_sdp_nr < 0) {
+ dev_err(dp->dev, "failed to send audio infoframe\n");
+ dw_dp_audio_unprepare(bridge, connector);
+ return dp->audio_sdp_nr;
+ }
+
+ dev_dbg(dp->dev, "audio prepare with %d channels using DAI=%d\n",
+ dp->audio_channels, dp->audio_interface);
+
+ return 0;
+}
+
+static void dw_dp_audio_shutdown(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio shutdown\n");
+
+ dw_dp_audio_unprepare(bridge, connector);
+ pm_runtime_put_autosuspend(dp->dev);
+}
+
+static int dw_dp_audio_mute_stream(struct drm_bridge *bridge,
+ struct drm_connector *connector,
+ bool enable, int direction)
+{
+ struct dw_dp *dp = bridge_to_dp(bridge);
+
+ dev_dbg(dp->dev, "audio %smute\n", enable ? "" : "un");
+
+ regmap_update_bits(dp->regmap, DW_DP_AUD_CONFIG1, AUDIO_MUTE,
+ FIELD_PREP(AUDIO_MUTE, enable));
+
+ return 0;
+}
+
static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
@@ -1899,6 +2143,11 @@ static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
.detect = dw_dp_bridge_detect,
.edid_read = dw_dp_bridge_edid_read,
.oob_notify = dw_dp_bridge_oob_notify,
+
+ .dp_audio_startup = dw_dp_audio_startup,
+ .dp_audio_prepare = dw_dp_audio_prepare,
+ .dp_audio_shutdown = dw_dp_audio_shutdown,
+ .dp_audio_mute_stream = dw_dp_audio_mute_stream,
};
static int dw_dp_link_retrain(struct dw_dp *dp)
@@ -2057,10 +2306,20 @@ int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
bridge = &dp->bridge;
bridge->of_node = dev->of_node;
- bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+ bridge->ops = DRM_BRIDGE_OP_DP_AUDIO |
+ DRM_BRIDGE_OP_DETECT |
+ DRM_BRIDGE_OP_EDID |
+ DRM_BRIDGE_OP_HPD;
bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
bridge->ycbcr_420_allowed = true;
+ dp->audio_interface = DW_DP_AUDIO_UNUSED;
+ dp->audio_sdp_nr = -1;
+ bridge->hdmi_audio_dev = dev;
+ bridge->hdmi_audio_max_i2s_playback_channels = 8;
+ bridge->hdmi_audio_dai_port = 1;
+ bridge->hdmi_audio_spdif_playback = true;
+
drm_bridge_add(bridge);
dp->aux.dev = dev;
--
2.53.0
^ permalink raw reply related [flat|nested] 41+ messages in thread* Re: [PATCH v6 16/16] drm/bridge: synopsys: dw-dp: Add audio support
2026-07-24 18:03 ` Sebastian Reichel
(?)
@ 2026-07-24 18:34 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-07-24 18:34 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: robh, conor+dt, devicetree, dri-devel
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] DRM atomic_disable zeroes the SDP slot allocator bitmap without invalidating the audio subsystem's active SDP slot (audio_sdp_nr), causing cross-subsystem races and hardware state corruption.
--
--- Patch [16]: [PATCH v6 16/16] drm/bridge: synopsys: dw-dp: Add audio support ---
commit 9b3a7d6fa62f20557e06c0ea7d9cc504eddb75d9
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
drm/bridge: synopsys: dw-dp: Add audio support
Implement audio support for the Synopsys DesignWare DisplayPort
controller.
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> index 44a13b5d62d39..c7d6f63b5e9a1 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
[ ... ]
> @@ -1886,6 +1924,212 @@ static void dw_dp_bridge_oob_notify(struct drm_bridge *bridge,
[ ... ]
> +static void dw_dp_audio_unprepare(struct drm_bridge *bridge,
> + struct drm_connector *connector)
> +{
> + struct dw_dp *dp = bridge_to_dp(bridge);
> +
> + if (dp->audio_sdp_nr >= 0) {
> + dw_dp_clear_sdp(dp, dp->audio_sdp_nr);
> + dp->audio_sdp_nr = -1;
> + }
[Severity: High]
Does this leave dp->audio_sdp_nr dangling if the display is disabled while
audio is active?
Looking at dw_dp_bridge_atomic_disable(), the SDP allocation bitmap is
bulk-cleared without resetting the audio subsystem's active SDP slot:
drivers/gpu/drm/bridge/synopsys/dw-dp.c:dw_dp_bridge_atomic_disable() {
...
scoped_guard(mutex, &dp->sdp_lock)
bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
...
}
If userspace triggers a display disable, dw_dp_bridge_atomic_disable() zeroes
the bitmap without resetting dp->audio_sdp_nr. When the display is re-enabled,
dw_dp_bridge_atomic_enable() might allocate that same slot for a video SDP.
If userspace later stops the audio stream, dw_dp_audio_unprepare() would see
the stale dp->audio_sdp_nr and clear the hardware registers for the newly
allocated video SDP.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260724-synopsys-dw-dp-improvements-v6-0-041d99a19c4e@collabora.com?part=16
^ permalink raw reply [flat|nested] 41+ messages in thread