[PATCH v5 00/10] Add HDMI 2.0 support to DW HDMI QP TX

[PATCH v5 00/10] Add HDMI 2.0 support to DW HDMI QP TX

[Cristian Ciocaltea]

Enable HDMI 2.0 display modes (e.g. 4K@60Hz) on the Synopsys DW HDMI QP
TX controller, as found in Rockchip RK3576 & RK3588 SoCs, by adding SCDC
management for high TMDS clock ratio and scrambling.

Since SCDC state is lost on sink disconnects, the bridge driver needs to
trigger a CRTC reset during connector detection.  To support this, the
series introduces an atomic-aware detect_ctx bridge hook and a
drm_bridge_detect_ctx() helper (patches 1-4), then uses them to
implement the SCDC scrambling feature (patch 5).

Patches 6-8 are minor cleanups in the dw-hdmi-qp and Rockchip platform
drivers.  Patches 9-10 improve HPD handling by deferring IRQ
registration until the connector is fully initialized and restricting
HPD events to the affected connector.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
Changes in v5:
- Added new patches: 1/10, 3/10, 6/10, 7/10, 8/10
- Removed redundant no-op error check in drm_bridge_helper_reset_crtc()
  (patch 1)
- Removed the EDEADLK retry loop from the bridge .detect_ctx() callback,
  as that's already handled in the drm_bridge_detect_ctx() helper or by
  the caller when ctx is provided (patch 2)
- Refactored drm_bridge_detect() to delegate to drm_bridge_detect_ctx()
  and added a WARN_ON for unexpected negative return values (patch 2)
- Split the bridge-connector .detect_ctx() switch into a preparatory
  patch to use cached connector status in .get_modes() (patch 3)
- Improved error handling in SCDC scrambling setup: roll back high TMDS
  clock ratio on scrambling failure, reset scramb_enabled flag on
  set_scramb failure, and add SCDC version read/write error checks
  (patch 5)
- Annotated scramb_enabled with READ_ONCE/WRITE_ONCE for cross-context
  access between modeset paths and the scrambling work item (patch 5)
- Renamed SCDC_MIN_SOURCE_VERSION to SCDC_MAX_SOURCE_VERSION (patch 5)
- Rate limited i2c error messages (patch 6)
- Added missing newlines in dev_err_probe() messages (patch 7)
- Replaced indirect device pointer accesses with local dev variable in
  bind() (patch 8)
- Split the HPD connector restriction (formerly patch 4/4): register HPD
  IRQ after connector setup first (patch 9), then restrict HPD event to
  the affected connector (patch 10); also collected R-b from Heiko
- Rebased onto latest drm-misc-next
- Link to v4: https://lore.kernel.org/r/20260303-dw-hdmi-qp-scramb-v4-0-317d3b8bd219@collabora.com

Changes in v4:
- Fixed conflicts while rebasing onto latest drm-misc-next
- Link to v3: https://lore.kernel.org/r/20260119-dw-hdmi-qp-scramb-v3-0-bd8611730fc1@collabora.com

Changes in v3:
- Used drm_bridge_helper_reset_crtc() helper to reset the display
  pipeline and got rid of some boilerplate code (Maxime)
- Rebased onto latest drm-misc-next
- Link to v2: https://lore.kernel.org/r/20260113-dw-hdmi-qp-scramb-v2-0-ae7b2c58d24d@collabora.com

Changes in v2:
- Collected Tested-by tags from Diederik and Maud
- Rebased onto latest drm-misc-next
- Ensured the recently introduced 'no-hpd' support for dealing with
  unconnected/repurposed/broken HPD pin is limited to HDMI 1.4 rates
- Link to v1: https://lore.kernel.org/r/20251203-dw-hdmi-qp-scramb-v1-0-836fe7401a69@collabora.com

---
Cristian Ciocaltea (10):
      drm/bridge: Remove redundant error check in drm_bridge_helper_reset_crtc()
      drm/bridge: Add detect_ctx hook and drm_bridge_detect_ctx() helper
      drm/bridge-connector: Use cached connector status in .get_modes()
      drm/bridge-connector: Switch to .detect_ctx() for connector detection
      drm/bridge: dw-hdmi-qp: Add HDMI 2.0 SCDC scrambling and high TMDS clock ratio support
      drm/bridge: dw-hdmi-qp: Rate limit i2c read error messages
      drm/rockchip: dw_hdmi_qp: Add missing newlines in dev_err_probe() messages
      drm/rockchip: dw_hdmi_qp: Use local dev variable consistently in bind()
      drm/rockchip: dw_hdmi_qp: Register HPD IRQ after connector setup
      drm/rockchip: dw_hdmi_qp: Restrict HPD event to the affected connector

 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c   | 192 ++++++++++++++++++++++---
 drivers/gpu/drm/display/drm_bridge_connector.c |  75 +++++-----
 drivers/gpu/drm/drm_bridge.c                   |  66 ++++++++-
 drivers/gpu/drm/drm_bridge_helper.c            |   2 -
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c |  68 ++++-----
 include/drm/drm_bridge.h                       |  43 +++++-
 6 files changed, 344 insertions(+), 102 deletions(-)
---
base-commit: 03af6c3afc4893988ceed54531f5dde4bebd6024
change-id: 20251203-dw-hdmi-qp-scramb-cdbd8b57ccf9

[PATCH v5 01/10] drm/bridge: Remove redundant error check in drm_bridge_helper_reset_crtc()

[Cristian Ciocaltea]

Remove the no-op error check after drm_atomic_helper_reset_crtc() since
the goto target is the immediately following label and the return value
is already propagated correctly without it.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/drm_bridge_helper.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_bridge_helper.c b/drivers/gpu/drm/drm_bridge_helper.c
index 420f29cf3e54..0a3c8fee66b3 100644
--- a/drivers/gpu/drm/drm_bridge_helper.c
+++ b/drivers/gpu/drm/drm_bridge_helper.c
@@ -50,8 +50,6 @@ int drm_bridge_helper_reset_crtc(struct drm_bridge *bridge,
 
 	crtc = connector->state->crtc;
 	ret = drm_atomic_helper_reset_crtc(crtc, ctx);
-	if (ret)
-		goto out;
 
 out:
 	drm_modeset_unlock(&dev->mode_config.connection_mutex);

-- 
2.53.0

[PATCH v5 02/10] drm/bridge: Add detect_ctx hook and drm_bridge_detect_ctx() helper

[Cristian Ciocaltea]

Add an atomic-aware .detect_ctx() callback to drm_bridge_funcs and a
drm_bridge_detect_ctx() helper that accepts an optional
drm_modeset_acquire_ctx.

This enables bridge drivers to perform operations requiring modeset
locking during connector detection, such as SCDC management for HDMI
2.0.  When both ->detect_ctx and ->detect are defined, the former takes
precedence.  When ctx is NULL, locking is managed internally with EDEADLK
retry.

Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/drm_bridge.c | 66 ++++++++++++++++++++++++++++++++++++++++----
 include/drm/drm_bridge.h     | 43 +++++++++++++++++++++++++----
 2 files changed, 98 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 986e4c79a4e0..a5c6c2ea4ba6 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -1361,9 +1361,9 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
  * @connector: attached connector
  *
  * If the bridge supports output detection, as reported by the
- * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the
- * bridge and return the connection status. Otherwise return
- * connector_status_unknown.
+ * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect_ctx
+ * or &drm_bridge_funcs.detect for the bridge and return the connection status.
+ * Otherwise return connector_status_unknown.
  *
  * RETURNS:
  * The detection status on success, or connector_status_unknown if the bridge
@@ -1372,12 +1372,68 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
 enum drm_connector_status
 drm_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
 {
+	return drm_bridge_detect_ctx(bridge, connector, NULL);
+}
+EXPORT_SYMBOL_GPL(drm_bridge_detect);
+
+/**
+ * drm_bridge_detect_ctx - check if anything is attached to the bridge output
+ * @bridge: bridge control structure
+ * @connector: attached connector
+ * @ctx: acquire_ctx, or NULL to let this function handle locking
+ *
+ * If the bridge supports output detection, as reported by the
+ * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect_ctx
+ * or &drm_bridge_funcs.detect for the bridge and return the connection status.
+ * Otherwise return connector_status_unknown.
+ *
+ * RETURNS:
+ * The detection status on success, or connector_status_unknown if the bridge
+ * doesn't support output detection.
+ * If @ctx is set, it might also return -EDEADLK.
+ */
+int drm_bridge_detect_ctx(struct drm_bridge *bridge,
+			  struct drm_connector *connector,
+			  struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_modeset_acquire_ctx br_ctx;
+	int ret;
+
 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))
 		return connector_status_unknown;
 
-	return bridge->funcs->detect(bridge, connector);
+	if (!bridge->funcs->detect_ctx)
+		return bridge->funcs->detect(bridge, connector);
+
+	if (ctx) {
+		ret = bridge->funcs->detect_ctx(bridge, connector, ctx);
+		if (ret == -EDEADLK)
+			return ret;
+
+		goto out;
+	}
+
+	drm_modeset_acquire_init(&br_ctx, 0);
+retry:
+	ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex,
+			       &br_ctx);
+	if (!ret)
+		ret = bridge->funcs->detect_ctx(bridge, connector, &br_ctx);
+
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&br_ctx);
+		goto retry;
+	}
+
+	drm_modeset_drop_locks(&br_ctx);
+	drm_modeset_acquire_fini(&br_ctx);
+out:
+	if (WARN_ON(ret < 0))
+		ret = connector_status_unknown;
+
+	return ret;
 }
-EXPORT_SYMBOL_GPL(drm_bridge_detect);
+EXPORT_SYMBOL_GPL(drm_bridge_detect_ctx);
 
 /**
  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index d6cd0f5af045..6c751b96c3c9 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -535,10 +535,12 @@ struct drm_bridge_funcs {
 	 *
 	 * Check if anything is attached to the bridge output.
 	 *
-	 * This callback is optional, if not implemented the bridge will be
-	 * considered as always having a component attached to its output.
-	 * Bridges that implement this callback shall set the
-	 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
+	 * This is the non-atomic version of detect_ctx() callback, and is
+	 * optional. If both are implemented, it is ignored. If none is
+	 * implemented, the bridge will be considered as always having a
+	 * component attached to its output. Bridges that implement this
+	 * callback shall set the DRM_BRIDGE_OP_DETECT flag in their
+	 * &drm_bridge->ops.
 	 *
 	 * RETURNS:
 	 *
@@ -547,6 +549,32 @@ struct drm_bridge_funcs {
 	enum drm_connector_status (*detect)(struct drm_bridge *bridge,
 					    struct drm_connector *connector);
 
+	/**
+	 * @detect_ctx:
+	 *
+	 * Check if anything is attached to the bridge output.
+	 *
+	 * This is the atomic version of detect() callback, and is optional.
+	 * If both are implemented, it takes precedence. If none is implemented,
+	 * the bridge will be considered as always having a component attached
+	 * to its output. Bridges that implement this callback shall set the
+	 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
+	 *
+	 * To avoid races against concurrent connector state updates, the
+	 * helper libraries always call this with ctx set to a valid context,
+	 * and &drm_mode_config.connection_mutex will always be locked with
+	 * the ctx parameter set to this ctx. This allows taking additional
+	 * locks as required.
+	 *
+	 * RETURNS:
+	 *
+	 * &drm_connector_status indicating the bridge output status,
+	 * or the error code returned by drm_modeset_lock(), -EDEADLK.
+	 */
+	int (*detect_ctx)(struct drm_bridge *bridge,
+			  struct drm_connector *connector,
+			  struct drm_modeset_acquire_ctx *ctx);
+
 	/**
 	 * @get_modes:
 	 *
@@ -1002,8 +1030,8 @@ struct drm_bridge_timings {
 enum drm_bridge_ops {
 	/**
 	 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
-	 * its output. Bridges that set this flag shall implement the
-	 * &drm_bridge_funcs->detect callback.
+	 * its output. Bridges that set this flag shall implement either the
+	 * &drm_bridge_funcs->detect or &drm_bridge_funcs->detect_ctx callbacks.
 	 */
 	DRM_BRIDGE_OP_DETECT = BIT(0),
 	/**
@@ -1565,6 +1593,9 @@ drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
 
 enum drm_connector_status
 drm_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector);
+int drm_bridge_detect_ctx(struct drm_bridge *bridge,
+			  struct drm_connector *connector,
+			  struct drm_modeset_acquire_ctx *ctx);
 int drm_bridge_get_modes(struct drm_bridge *bridge,
 			 struct drm_connector *connector);
 const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge,

-- 
2.53.0

[PATCH v5 03/10] drm/bridge-connector: Use cached connector status in .get_modes()

[Cristian Ciocaltea]

Replace the active drm_bridge_connector_detect() call in get_modes()
with a read of the already-cached connector->status.

The .get_modes() callback is only invoked from
drm_helper_probe_single_connector_modes(), which has already retrieved
the connector status.  Calling detect again is redundant and triggers a
duplicate hotplug event.  This is also a prerequisite for switching to
the .detect_ctx() hook, which requires a drm_modeset_acquire_ctx not
available in the .get_modes() path.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/display/drm_bridge_connector.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 39cc18f78eda..575c09e9cb73 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -294,12 +294,10 @@ static const struct drm_connector_funcs drm_bridge_connector_funcs = {
 static int drm_bridge_connector_get_modes_edid(struct drm_connector *connector,
 					       struct drm_bridge *bridge)
 {
-	enum drm_connector_status status;
 	const struct drm_edid *drm_edid;
 	int n;
 
-	status = drm_bridge_connector_detect(connector, false);
-	if (status != connector_status_connected)
+	if (connector->status != connector_status_connected)
 		goto no_edid;
 
 	drm_edid = drm_bridge_edid_read(bridge, connector);

-- 
2.53.0

[PATCH v5 04/10] drm/bridge-connector: Switch to .detect_ctx() for connector detection

[Cristian Ciocaltea]

Use the atomic .detect_ctx() connector helper hook and invoke
drm_bridge_detect_ctx() to propagate the modeset acquire context to
bridge drivers.

This enables bridge drivers to perform modeset operations during
detection, which is needed for managing SCDC state lost on sink
disconnects in HDMI 2.0 scenarios.

Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/display/drm_bridge_connector.c | 71 ++++++++++++++------------
 1 file changed, 37 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 575c09e9cb73..ca2ba7630f6b 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -208,39 +208,6 @@ static void drm_bridge_connector_disable_hpd(struct drm_connector *connector)
  * Bridge Connector Functions
  */
 
-static enum drm_connector_status
-drm_bridge_connector_detect(struct drm_connector *connector, bool force)
-{
-	struct drm_bridge_connector *bridge_connector =
-		to_drm_bridge_connector(connector);
-	struct drm_bridge *detect = bridge_connector->bridge_detect;
-	struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
-	enum drm_connector_status status;
-
-	if (detect) {
-		status = detect->funcs->detect(detect, connector);
-
-		if (hdmi)
-			drm_atomic_helper_connector_hdmi_hotplug(connector, status);
-
-		drm_bridge_connector_hpd_notify(connector, status);
-	} else {
-		switch (connector->connector_type) {
-		case DRM_MODE_CONNECTOR_DPI:
-		case DRM_MODE_CONNECTOR_LVDS:
-		case DRM_MODE_CONNECTOR_DSI:
-		case DRM_MODE_CONNECTOR_eDP:
-			status = connector_status_connected;
-			break;
-		default:
-			status = connector_status_unknown;
-			break;
-		}
-	}
-
-	return status;
-}
-
 static void drm_bridge_connector_force(struct drm_connector *connector)
 {
 	struct drm_bridge_connector *bridge_connector =
@@ -278,7 +245,6 @@ static void drm_bridge_connector_reset(struct drm_connector *connector)
 
 static const struct drm_connector_funcs drm_bridge_connector_funcs = {
 	.reset = drm_bridge_connector_reset,
-	.detect = drm_bridge_connector_detect,
 	.force = drm_bridge_connector_force,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
@@ -291,6 +257,42 @@ static const struct drm_connector_funcs drm_bridge_connector_funcs = {
  * Bridge Connector Helper Functions
  */
 
+static int drm_bridge_connector_detect_ctx(struct drm_connector *connector,
+					   struct drm_modeset_acquire_ctx *ctx,
+					   bool force)
+{
+	struct drm_bridge_connector *bridge_connector =
+		to_drm_bridge_connector(connector);
+	struct drm_bridge *detect = bridge_connector->bridge_detect;
+	struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
+	int ret;
+
+	if (detect) {
+		ret = drm_bridge_detect_ctx(detect, connector, ctx);
+		if (ret < 0)
+			return ret;
+
+		if (hdmi)
+			drm_atomic_helper_connector_hdmi_hotplug(connector, ret);
+
+		drm_bridge_connector_hpd_notify(connector, ret);
+	} else {
+		switch (connector->connector_type) {
+		case DRM_MODE_CONNECTOR_DPI:
+		case DRM_MODE_CONNECTOR_LVDS:
+		case DRM_MODE_CONNECTOR_DSI:
+		case DRM_MODE_CONNECTOR_eDP:
+			ret = connector_status_connected;
+			break;
+		default:
+			ret = connector_status_unknown;
+			break;
+		}
+	}
+
+	return ret;
+}
+
 static int drm_bridge_connector_get_modes_edid(struct drm_connector *connector,
 					       struct drm_bridge *bridge)
 {
@@ -382,6 +384,7 @@ static int drm_bridge_connector_atomic_check(struct drm_connector *connector,
 
 static const struct drm_connector_helper_funcs drm_bridge_connector_helper_funcs = {
 	.get_modes = drm_bridge_connector_get_modes,
+	.detect_ctx = drm_bridge_connector_detect_ctx,
 	.mode_valid = drm_bridge_connector_mode_valid,
 	.enable_hpd = drm_bridge_connector_enable_hpd,
 	.disable_hpd = drm_bridge_connector_disable_hpd,

-- 
2.53.0

[PATCH v5 05/10] drm/bridge: dw-hdmi-qp: Add HDMI 2.0 SCDC scrambling and high TMDS clock ratio support

[Cristian Ciocaltea]

Enable HDMI 2.0 display modes (e.g. 4K@60Hz) by adding SCDC management
for the high TMDS clock ratio and scrambling, required when the TMDS
character rate exceeds the 340 MHz HDMI 1.4b limit.

A periodic work item monitors the sink's scrambling status to recover
from sink-side resets.  On hotplug detect, if SCDC scrambling state is
out of sync with the driver, trigger a CRTC reset to re-establish the
link.

Reject modes requiring TMDS rates above 600 MHz, as those fall in the
HDMI 2.1 FRL domain which is not supported. In no_hpd configurations,
further restrict to 340 MHz since SCDC requires a connected sink.

Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 188 ++++++++++++++++++++++++---
 1 file changed, 172 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index d649a1cf07f5..c482a8e7da25 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -2,6 +2,7 @@
 /*
  * Copyright (c) 2021-2022 Rockchip Electronics Co., Ltd.
  * Copyright (c) 2024 Collabora Ltd.
+ * Copyright (c) 2025 Amazon.com, Inc. or its affiliates.
  *
  * Author: Algea Cao <algea.cao@rock-chips.com>
  * Author: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
@@ -21,9 +22,11 @@
 #include <drm/display/drm_hdmi_helper.h>
 #include <drm/display/drm_hdmi_cec_helper.h>
 #include <drm/display/drm_hdmi_state_helper.h>
+#include <drm/display/drm_scdc_helper.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_bridge_helper.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_modes.h>
@@ -39,7 +42,9 @@
 #define DDC_SEGMENT_ADDR	0x30
 
 #define HDMI14_MAX_TMDSCLK	340000000
+#define HDMI20_MAX_TMDSRATE	600000000
 
+#define SCDC_MAX_SOURCE_VERSION	0x1
 #define SCRAMB_POLL_DELAY_MS	3000
 
 /*
@@ -164,6 +169,11 @@ struct dw_hdmi_qp {
 	} phy;
 
 	unsigned long ref_clk_rate;
+
+	struct drm_connector *curr_conn;
+	struct delayed_work scramb_work;
+	bool scramb_enabled;
+
 	struct regmap *regm;
 	int main_irq;
 
@@ -749,28 +759,124 @@ static struct i2c_adapter *dw_hdmi_qp_i2c_adapter(struct dw_hdmi_qp *hdmi)
 	return adap;
 }
 
+static bool dw_hdmi_qp_supports_scrambling(struct drm_display_info *display)
+{
+	if (!display->is_hdmi)
+		return false;
+
+	return display->hdmi.scdc.supported &&
+		display->hdmi.scdc.scrambling.supported;
+}
+
+static int dw_hdmi_qp_set_scramb(struct dw_hdmi_qp *hdmi)
+{
+	bool done;
+
+	dev_dbg(hdmi->dev, "set scrambling\n");
+
+	done = drm_scdc_set_high_tmds_clock_ratio(hdmi->curr_conn, true);
+	if (!done)
+		return -EIO;
+
+	done = drm_scdc_set_scrambling(hdmi->curr_conn, true);
+	if (!done) {
+		drm_scdc_set_high_tmds_clock_ratio(hdmi->curr_conn, false);
+		return -EIO;
+	}
+
+	schedule_delayed_work(&hdmi->scramb_work,
+			      msecs_to_jiffies(SCRAMB_POLL_DELAY_MS));
+	return 0;
+}
+
+static void dw_hdmi_qp_scramb_work(struct work_struct *work)
+{
+	struct dw_hdmi_qp *hdmi = container_of(to_delayed_work(work),
+					       struct dw_hdmi_qp,
+					       scramb_work);
+	if (READ_ONCE(hdmi->scramb_enabled) &&
+	    !drm_scdc_get_scrambling_status(hdmi->curr_conn))
+		dw_hdmi_qp_set_scramb(hdmi);
+}
+
+static void dw_hdmi_qp_enable_scramb(struct dw_hdmi_qp *hdmi)
+{
+	int ret;
+	u8 ver;
+
+	if (!dw_hdmi_qp_supports_scrambling(&hdmi->curr_conn->display_info))
+		return;
+
+	ret = drm_scdc_readb(hdmi->bridge.ddc, SCDC_SINK_VERSION, &ver);
+	if (ret) {
+		dev_err(hdmi->dev, "Failed to read SCDC_SINK_VERSION: %d\n", ret);
+		return;
+	}
+
+	ret = drm_scdc_writeb(hdmi->bridge.ddc, SCDC_SOURCE_VERSION,
+			      min_t(u8, ver, SCDC_MAX_SOURCE_VERSION));
+	if (ret) {
+		dev_err(hdmi->dev, "Failed to write SCDC_SOURCE_VERSION: %d\n", ret);
+		return;
+	}
+
+	WRITE_ONCE(hdmi->scramb_enabled, true);
+
+	ret = dw_hdmi_qp_set_scramb(hdmi);
+	if (ret) {
+		hdmi->scramb_enabled = false;
+		return;
+	}
+
+	dw_hdmi_qp_write(hdmi, 1, SCRAMB_CONFIG0);
+
+	/* Wait at least 1 ms before resuming TMDS transmission */
+	usleep_range(1000, 5000);
+}
+
+static void dw_hdmi_qp_disable_scramb(struct dw_hdmi_qp *hdmi)
+{
+	if (!hdmi->scramb_enabled)
+		return;
+
+	dev_dbg(hdmi->dev, "disable scrambling\n");
+
+	WRITE_ONCE(hdmi->scramb_enabled, false);
+	cancel_delayed_work_sync(&hdmi->scramb_work);
+
+	dw_hdmi_qp_write(hdmi, 0, SCRAMB_CONFIG0);
+
+	if (hdmi->curr_conn->status == connector_status_connected) {
+		drm_scdc_set_scrambling(hdmi->curr_conn, false);
+		drm_scdc_set_high_tmds_clock_ratio(hdmi->curr_conn, false);
+	}
+}
+
 static void dw_hdmi_qp_bridge_atomic_enable(struct drm_bridge *bridge,
 					    struct drm_atomic_state *state)
 {
 	struct dw_hdmi_qp *hdmi = bridge->driver_private;
 	struct drm_connector_state *conn_state;
-	struct drm_connector *connector;
 	unsigned int op_mode;
 
-	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
-	if (WARN_ON(!connector))
+	hdmi->curr_conn = drm_atomic_get_new_connector_for_encoder(state,
+								   bridge->encoder);
+	if (WARN_ON(!hdmi->curr_conn))
 		return;
 
-	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	conn_state = drm_atomic_get_new_connector_state(state, hdmi->curr_conn);
 	if (WARN_ON(!conn_state))
 		return;
 
-	if (connector->display_info.is_hdmi) {
+	if (hdmi->curr_conn->display_info.is_hdmi) {
 		dev_dbg(hdmi->dev, "%s mode=HDMI %s rate=%llu bpc=%u\n", __func__,
 			drm_hdmi_connector_get_output_format_name(conn_state->hdmi.output_format),
 			conn_state->hdmi.tmds_char_rate, conn_state->hdmi.output_bpc);
 		op_mode = 0;
 		hdmi->tmds_char_rate = conn_state->hdmi.tmds_char_rate;
+
+		if (conn_state->hdmi.tmds_char_rate > HDMI14_MAX_TMDSCLK)
+			dw_hdmi_qp_enable_scramb(hdmi);
 	} else {
 		dev_dbg(hdmi->dev, "%s mode=DVI\n", __func__);
 		op_mode = OPMODE_DVI;
@@ -781,7 +887,7 @@ static void dw_hdmi_qp_bridge_atomic_enable(struct drm_bridge *bridge,
 	dw_hdmi_qp_mod(hdmi, HDCP2_BYPASS, HDCP2_BYPASS, HDCP2LOGIC_CONFIG0);
 	dw_hdmi_qp_mod(hdmi, op_mode, OPMODE_DVI, LINK_CONFIG0);
 
-	drm_atomic_helper_connector_hdmi_update_infoframes(connector, state);
+	drm_atomic_helper_connector_hdmi_update_infoframes(hdmi->curr_conn, state);
 }
 
 static void dw_hdmi_qp_bridge_atomic_disable(struct drm_bridge *bridge,
@@ -791,14 +897,49 @@ static void dw_hdmi_qp_bridge_atomic_disable(struct drm_bridge *bridge,
 
 	hdmi->tmds_char_rate = 0;
 
+	dw_hdmi_qp_disable_scramb(hdmi);
+
+	hdmi->curr_conn = NULL;
 	hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
 }
 
-static enum drm_connector_status
-dw_hdmi_qp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
+static int dw_hdmi_qp_reset_crtc(struct dw_hdmi_qp *hdmi,
+				 struct drm_connector *connector,
+				 struct drm_modeset_acquire_ctx *ctx)
+{
+	u8 config;
+	int ret;
+
+	ret = drm_scdc_readb(hdmi->bridge.ddc, SCDC_TMDS_CONFIG, &config);
+	if (ret < 0) {
+		dev_err(hdmi->dev, "Failed to read TMDS config: %d\n", ret);
+		return ret;
+	}
+
+	if (!!(config & SCDC_SCRAMBLING_ENABLE) == hdmi->scramb_enabled)
+		return 0;
+
+	drm_atomic_helper_connector_hdmi_hotplug(connector,
+						 connector_status_connected);
+	/*
+	 * Conform to HDMI 2.0 spec by ensuring scrambled data is not sent
+	 * before configuring the sink scrambling, as well as suspending any
+	 * TMDS transmission while changing the TMDS clock rate in the sink.
+	 */
+
+	dev_dbg(hdmi->dev, "resetting crtc\n");
+
+	return drm_bridge_helper_reset_crtc(&hdmi->bridge, ctx);
+}
+
+static int dw_hdmi_qp_bridge_detect_ctx(struct drm_bridge *bridge,
+					struct drm_connector *connector,
+					struct drm_modeset_acquire_ctx *ctx)
 {
 	struct dw_hdmi_qp *hdmi = bridge->driver_private;
+	enum drm_connector_status status;
 	const struct drm_edid *drm_edid;
+	int ret;
 
 	if (hdmi->no_hpd) {
 		drm_edid = drm_edid_read_ddc(connector, bridge->ddc);
@@ -808,7 +949,20 @@ dw_hdmi_qp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connec
 			return connector_status_disconnected;
 	}
 
-	return hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
+	status = hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
+
+	dev_dbg(hdmi->dev, "%s status=%d scramb=%d\n", __func__,
+		status, hdmi->scramb_enabled);
+
+	if (status == connector_status_connected && hdmi->scramb_enabled) {
+		ret = dw_hdmi_qp_reset_crtc(hdmi, connector, ctx);
+		if (ret == -EDEADLK)
+			return ret;
+		if (ret < 0)
+			status = connector_status_unknown;
+	}
+
+	return status;
 }
 
 static const struct drm_edid *
@@ -832,12 +986,12 @@ dw_hdmi_qp_bridge_tmds_char_rate_valid(const struct drm_bridge *bridge,
 {
 	struct dw_hdmi_qp *hdmi = bridge->driver_private;
 
-	/*
-	 * TODO: when hdmi->no_hpd is 1 we must not support modes that
-	 * require scrambling, including every mode with a clock above
-	 * HDMI14_MAX_TMDSCLK.
-	 */
-	if (rate > HDMI14_MAX_TMDSCLK) {
+	if (hdmi->no_hpd && rate > HDMI14_MAX_TMDSCLK) {
+		dev_dbg(hdmi->dev, "Unsupported TMDS char rate in no_hpd mode: %lld\n", rate);
+		return MODE_CLOCK_HIGH;
+	}
+
+	if (rate > HDMI20_MAX_TMDSRATE) {
 		dev_dbg(hdmi->dev, "Unsupported TMDS char rate: %lld\n", rate);
 		return MODE_CLOCK_HIGH;
 	}
@@ -1197,7 +1351,7 @@ static const struct drm_bridge_funcs dw_hdmi_qp_bridge_funcs = {
 	.atomic_reset = drm_atomic_helper_bridge_reset,
 	.atomic_enable = dw_hdmi_qp_bridge_atomic_enable,
 	.atomic_disable = dw_hdmi_qp_bridge_atomic_disable,
-	.detect = dw_hdmi_qp_bridge_detect,
+	.detect_ctx = dw_hdmi_qp_bridge_detect_ctx,
 	.edid_read = dw_hdmi_qp_bridge_edid_read,
 	.hdmi_tmds_char_rate_valid = dw_hdmi_qp_bridge_tmds_char_rate_valid,
 	.hdmi_clear_avi_infoframe = dw_hdmi_qp_bridge_clear_avi_infoframe,
@@ -1287,6 +1441,8 @@ struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev,
 	if (IS_ERR(hdmi))
 		return ERR_CAST(hdmi);
 
+	INIT_DELAYED_WORK(&hdmi->scramb_work, dw_hdmi_qp_scramb_work);
+
 	hdmi->dev = dev;
 
 	regs = devm_platform_ioremap_resource(pdev, 0);

-- 
2.53.0

[PATCH v5 06/10] drm/bridge: dw-hdmi-qp: Rate limit i2c read error messages

[Cristian Ciocaltea]

During EDID reads, repeated i2c errors can flood the kernel log:

[   25.361716] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
[   25.363376] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
...
[   25.368671] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
[   25.369440] dwhdmiqp-rockchip fde80000.hdmi: failed to get edid

Switch to dev_err_ratelimited() in dw_hdmi_qp_i2c_read() to reduce log
spam while still reporting the condition.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index c482a8e7da25..36fbd3831bc4 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -573,7 +573,7 @@ static int dw_hdmi_qp_i2c_read(struct dw_hdmi_qp *hdmi,
 				dev_dbg_ratelimited(hdmi->dev,
 						    "i2c read timed out\n");
 			else
-				dev_err(hdmi->dev, "i2c read timed out\n");
+				dev_err_ratelimited(hdmi->dev, "i2c read timed out\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EAGAIN;
 		}
@@ -584,7 +584,7 @@ static int dw_hdmi_qp_i2c_read(struct dw_hdmi_qp *hdmi,
 				dev_dbg_ratelimited(hdmi->dev,
 						    "i2c read error\n");
 			else
-				dev_err(hdmi->dev, "i2c read error\n");
+				dev_err_ratelimited(hdmi->dev, "i2c read error\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EIO;
 		}

-- 
2.53.0

[PATCH v5 07/10] drm/rockchip: dw_hdmi_qp: Add missing newlines in dev_err_probe() messages

[Cristian Ciocaltea]

Add the missing trailing newlines to a couple of dev_err_probe() calls
in dw_hdmi_qp_rockchip_bind().

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index c78db7f8ab6c..d9333ad8996b 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -589,14 +589,14 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	drm_encoder_helper_add(encoder, &dw_hdmi_qp_rockchip_encoder_helper_funcs);
 	ret = drmm_encoder_init(drm, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
 	if (ret)
-		return dev_err_probe(hdmi->dev, ret, "Failed to init encoder");
+		return dev_err_probe(hdmi->dev, ret, "Failed to init encoder\n");
 
 	platform_set_drvdata(pdev, hdmi);
 
 	hdmi->hdmi = dw_hdmi_qp_bind(pdev, encoder, &plat_data);
 	if (IS_ERR(hdmi->hdmi))
 		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->hdmi),
-				     "Failed to bind dw-hdmi-qp");
+				     "Failed to bind dw-hdmi-qp\n");
 
 	connector = drm_bridge_connector_init(drm, encoder);
 	if (IS_ERR(connector))

-- 
2.53.0

[PATCH v5 08/10] drm/rockchip: dw_hdmi_qp: Use local dev variable consistently in bind()

[Cristian Ciocaltea]

Replace indirect struct device accesses via hdmi->dev and pdev->dev with
the local dev parameter already available in dw_hdmi_qp_rockchip_bind(),
for consistency and readability.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 33 +++++++++++++-------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index d9333ad8996b..618d2aaa5c7d 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -475,7 +475,7 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	struct clk *ref_clk;
 	int ret, irq, i;
 
-	if (!pdev->dev.of_node)
+	if (!dev->of_node)
 		return -ENODEV;
 
 	hdmi = drmm_kzalloc(drm, sizeof(*hdmi), GFP_KERNEL);
@@ -495,7 +495,7 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 		return dev_err_probe(dev, -ENODEV, "Missing platform ctrl ops\n");
 
 	hdmi->ctrl_ops = cfg->ctrl_ops;
-	hdmi->dev = &pdev->dev;
+	hdmi->dev = dev;
 	hdmi->port_id = -ENODEV;
 
 	/* Identify port ID by matching base IO address */
@@ -506,7 +506,7 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 		}
 	}
 	if (hdmi->port_id < 0)
-		return dev_err_probe(hdmi->dev, hdmi->port_id,
+		return dev_err_probe(dev, hdmi->port_id,
 				     "Failed to match HDMI port ID\n");
 
 	plat_data.phy_ops = cfg->phy_ops;
@@ -530,37 +530,36 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	hdmi->regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
 						       "rockchip,grf");
 	if (IS_ERR(hdmi->regmap))
-		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->regmap),
+		return dev_err_probe(dev, PTR_ERR(hdmi->regmap),
 				     "Unable to get rockchip,grf\n");
 
 	hdmi->vo_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
 							  "rockchip,vo-grf");
 	if (IS_ERR(hdmi->vo_regmap))
-		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->vo_regmap),
+		return dev_err_probe(dev, PTR_ERR(hdmi->vo_regmap),
 				     "Unable to get rockchip,vo-grf\n");
 
-	ret = devm_clk_bulk_get_all_enabled(hdmi->dev, &clks);
+	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
 	if (ret < 0)
-		return dev_err_probe(hdmi->dev, ret, "Failed to get clocks\n");
+		return dev_err_probe(dev, ret, "Failed to get clocks\n");
 
-	ref_clk = clk_get(hdmi->dev, "ref");
+	ref_clk = clk_get(dev, "ref");
 	if (IS_ERR(ref_clk))
-		return dev_err_probe(hdmi->dev, PTR_ERR(ref_clk),
+		return dev_err_probe(dev, PTR_ERR(ref_clk),
 				     "Failed to get ref clock\n");
 
 	plat_data.ref_clk_rate = clk_get_rate(ref_clk);
 	clk_put(ref_clk);
 
-	hdmi->frl_enable_gpio = devm_gpiod_get_optional(hdmi->dev, "frl-enable",
+	hdmi->frl_enable_gpio = devm_gpiod_get_optional(dev, "frl-enable",
 							GPIOD_OUT_LOW);
 	if (IS_ERR(hdmi->frl_enable_gpio))
-		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->frl_enable_gpio),
+		return dev_err_probe(dev, PTR_ERR(hdmi->frl_enable_gpio),
 				     "Failed to request FRL enable GPIO\n");
 
 	hdmi->phy = devm_of_phy_get_by_index(dev, dev->of_node, 0);
 	if (IS_ERR(hdmi->phy))
-		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->phy),
-				     "Failed to get phy\n");
+		return dev_err_probe(dev, PTR_ERR(hdmi->phy), "Failed to get phy\n");
 
 	cfg->ctrl_ops->io_init(hdmi);
 
@@ -578,7 +577,7 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	if (irq < 0)
 		return irq;
 
-	ret = devm_request_threaded_irq(hdmi->dev, irq,
+	ret = devm_request_threaded_irq(dev, irq,
 					cfg->ctrl_ops->hardirq_callback,
 					cfg->ctrl_ops->irq_callback,
 					IRQF_SHARED, "dw-hdmi-qp-hpd",
@@ -589,18 +588,18 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	drm_encoder_helper_add(encoder, &dw_hdmi_qp_rockchip_encoder_helper_funcs);
 	ret = drmm_encoder_init(drm, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
 	if (ret)
-		return dev_err_probe(hdmi->dev, ret, "Failed to init encoder\n");
+		return dev_err_probe(dev, ret, "Failed to init encoder\n");
 
 	platform_set_drvdata(pdev, hdmi);
 
 	hdmi->hdmi = dw_hdmi_qp_bind(pdev, encoder, &plat_data);
 	if (IS_ERR(hdmi->hdmi))
-		return dev_err_probe(hdmi->dev, PTR_ERR(hdmi->hdmi),
+		return dev_err_probe(dev, PTR_ERR(hdmi->hdmi),
 				     "Failed to bind dw-hdmi-qp\n");
 
 	connector = drm_bridge_connector_init(drm, encoder);
 	if (IS_ERR(connector))
-		return dev_err_probe(hdmi->dev, PTR_ERR(connector),
+		return dev_err_probe(dev, PTR_ERR(connector),
 				     "Failed to init bridge connector\n");
 
 	return drm_connector_attach_encoder(connector, encoder);

-- 
2.53.0

[PATCH v5 09/10] drm/rockchip: dw_hdmi_qp: Register HPD IRQ after connector setup

[Cristian Ciocaltea]

Move devm_request_threaded_irq() to the end of bind(), after
drm_bridge_connector_init() and drm_connector_attach_encoder(), to
ensure all DRM resources are ready before HPD interrupts can fire.

While at it, add error handling for drm_connector_attach_encoder().

Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index 618d2aaa5c7d..fbbe26f8730c 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -577,14 +577,6 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	if (irq < 0)
 		return irq;
 
-	ret = devm_request_threaded_irq(dev, irq,
-					cfg->ctrl_ops->hardirq_callback,
-					cfg->ctrl_ops->irq_callback,
-					IRQF_SHARED, "dw-hdmi-qp-hpd",
-					hdmi);
-	if (ret)
-		return ret;
-
 	drm_encoder_helper_add(encoder, &dw_hdmi_qp_rockchip_encoder_helper_funcs);
 	ret = drmm_encoder_init(drm, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
 	if (ret)
@@ -602,7 +594,15 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 		return dev_err_probe(dev, PTR_ERR(connector),
 				     "Failed to init bridge connector\n");
 
-	return drm_connector_attach_encoder(connector, encoder);
+	ret = drm_connector_attach_encoder(connector, encoder);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to attach connector\n");
+
+	return devm_request_threaded_irq(dev, irq,
+					 cfg->ctrl_ops->hardirq_callback,
+					 cfg->ctrl_ops->irq_callback,
+					 IRQF_SHARED, "dw-hdmi-qp-hpd",
+					 hdmi);
 }
 
 static void dw_hdmi_qp_rockchip_unbind(struct device *dev,

-- 
2.53.0

[PATCH v5 10/10] drm/rockchip: dw_hdmi_qp: Restrict HPD event to the affected connector

[Cristian Ciocaltea]

Switch from drm_helper_hpd_irq_event(), which polls all connectors, to
drm_connector_helper_hpd_irq_event(), which runs the detect cycle only
on the affected connector.

This avoids unnecessary work and redundant detect calls on unrelated
connectors.

Tested-by: Diederik de Haas <diederik@cknow-tech.com>
Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index fbbe26f8730c..d6338195a5b7 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -93,6 +93,7 @@ struct rockchip_hdmi_qp {
 	struct regmap *regmap;
 	struct regmap *vo_regmap;
 	struct rockchip_encoder encoder;
+	struct drm_connector *connector;
 	struct dw_hdmi_qp *hdmi;
 	struct phy *phy;
 	struct gpio_desc *frl_enable_gpio;
@@ -252,11 +253,10 @@ static void dw_hdmi_qp_rk3588_hpd_work(struct work_struct *work)
 	struct rockchip_hdmi_qp *hdmi = container_of(work,
 						     struct rockchip_hdmi_qp,
 						     hpd_work.work);
-	struct drm_device *drm = hdmi->encoder.encoder.dev;
 	bool changed;
 
-	if (drm) {
-		changed = drm_helper_hpd_irq_event(drm);
+	if (hdmi->connector) {
+		changed = drm_connector_helper_hpd_irq_event(hdmi->connector);
 		if (changed)
 			dev_dbg(hdmi->dev, "connector status changed\n");
 	}
@@ -467,7 +467,6 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 	struct dw_hdmi_qp_plat_data plat_data = {};
 	const struct rockchip_hdmi_qp_cfg *cfg;
 	struct drm_device *drm = data;
-	struct drm_connector *connector;
 	struct drm_encoder *encoder;
 	struct rockchip_hdmi_qp *hdmi;
 	struct resource *res;
@@ -589,12 +588,12 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 		return dev_err_probe(dev, PTR_ERR(hdmi->hdmi),
 				     "Failed to bind dw-hdmi-qp\n");
 
-	connector = drm_bridge_connector_init(drm, encoder);
-	if (IS_ERR(connector))
-		return dev_err_probe(dev, PTR_ERR(connector),
+	hdmi->connector = drm_bridge_connector_init(drm, encoder);
+	if (IS_ERR(hdmi->connector))
+		return dev_err_probe(dev, PTR_ERR(hdmi->connector),
 				     "Failed to init bridge connector\n");
 
-	ret = drm_connector_attach_encoder(connector, encoder);
+	ret = drm_connector_attach_encoder(hdmi->connector, encoder);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to attach connector\n");
 
@@ -612,6 +611,8 @@ static void dw_hdmi_qp_rockchip_unbind(struct device *dev,
 	struct rockchip_hdmi_qp *hdmi = dev_get_drvdata(dev);
 
 	cancel_delayed_work_sync(&hdmi->hpd_work);
+
+	hdmi->connector = NULL;
 }
 
 static const struct component_ops dw_hdmi_qp_rockchip_ops = {
@@ -646,8 +647,8 @@ static int __maybe_unused dw_hdmi_qp_rockchip_resume(struct device *dev)
 
 	dw_hdmi_qp_resume(dev, hdmi->hdmi);
 
-	if (hdmi->encoder.encoder.dev)
-		drm_helper_hpd_irq_event(hdmi->encoder.encoder.dev);
+	if (hdmi->connector)
+		drm_connector_helper_hpd_irq_event(hdmi->connector);
 
 	return 0;
 }

-- 
2.53.0

Re: [PATCH v5 07/10] drm/rockchip: dw_hdmi_qp: Add missing newlines in dev_err_probe() messages

[Heiko Stuebner]

Am Sonntag, 26. April 2026, 02:20:19 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
> Add the missing trailing newlines to a couple of dev_err_probe() calls
> in dw_hdmi_qp_rockchip_bind().
> 
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

Reviewed-by: Heiko Stuebner <heiko@sntech.de>

Re: [PATCH v5 08/10] drm/rockchip: dw_hdmi_qp: Use local dev variable consistently in bind()

[Heiko Stuebner]

Am Sonntag, 26. April 2026, 02:20:20 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
> Replace indirect struct device accesses via hdmi->dev and pdev->dev with
> the local dev parameter already available in dw_hdmi_qp_rockchip_bind(),
> for consistency and readability.
> 
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

Reviewed-by: Heiko Stuebner <heiko@sntech.de>

Re: [PATCH v5 06/10] drm/bridge: dw-hdmi-qp: Rate limit i2c read error messages

[Heiko Stuebner]

Am Sonntag, 26. April 2026, 02:20:18 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
> During EDID reads, repeated i2c errors can flood the kernel log:
> 
> [   25.361716] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
> [   25.363376] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
> ...
> [   25.368671] dwhdmiqp-rockchip fde80000.hdmi: i2c read error
> [   25.369440] dwhdmiqp-rockchip fde80000.hdmi: failed to get edid
> 
> Switch to dev_err_ratelimited() in dw_hdmi_qp_i2c_read() to reduce log
> spam while still reporting the condition.
> 
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

Reviewed-by: Heiko Stuebner <heiko@sntech.de>

Re: [PATCH v5 05/10] drm/bridge: dw-hdmi-qp: Add HDMI 2.0 SCDC scrambling and high TMDS clock ratio support

[Heiko Stuebner]

Am Sonntag, 26. April 2026, 02:20:17 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
> Enable HDMI 2.0 display modes (e.g. 4K@60Hz) by adding SCDC management
> for the high TMDS clock ratio and scrambling, required when the TMDS
> character rate exceeds the 340 MHz HDMI 1.4b limit.
> 
> A periodic work item monitors the sink's scrambling status to recover
> from sink-side resets.  On hotplug detect, if SCDC scrambling state is
> out of sync with the driver, trigger a CRTC reset to re-establish the
> link.
> 
> Reject modes requiring TMDS rates above 600 MHz, as those fall in the
> HDMI 2.1 FRL domain which is not supported. In no_hpd configurations,
> further restrict to 340 MHz since SCDC requires a connected sink.
> 
> Tested-by: Diederik de Haas <diederik@cknow-tech.com>
> Tested-by: Maud Spierings <maud_spierings@hotmail.com>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 188 ++++++++++++++++++++++++---
>  1 file changed, 172 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> index d649a1cf07f5..c482a8e7da25 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> @@ -2,6 +2,7 @@
>  /*
>   * Copyright (c) 2021-2022 Rockchip Electronics Co., Ltd.
>   * Copyright (c) 2024 Collabora Ltd.
> + * Copyright (c) 2025 Amazon.com, Inc. or its affiliates.

I have no real clue about the inner workings of hdmi, but that line
does make me curious, because no part of the patch authorship does
mention Amazon ;-) .

Also I think "or it's affiliates" might be way too broad, because this
can be essentially everyone. So noone in the future will know who to
ask on copyright questions.

Similarly when _somebody_ comes forward with "I hold a copyright on this"
no-one could verify this claim as well.

I somehow expect _one_ entity being specified, not possibly hundreds.


Heiko

Re: [PATCH v5 02/10] drm/bridge: Add detect_ctx hook and drm_bridge_detect_ctx() helper

[Heiko Stuebner]

Am Sonntag, 26. April 2026, 02:20:14 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
> Add an atomic-aware .detect_ctx() callback to drm_bridge_funcs and a
> drm_bridge_detect_ctx() helper that accepts an optional
> drm_modeset_acquire_ctx.
> 
> This enables bridge drivers to perform operations requiring modeset
> locking during connector detection, such as SCDC management for HDMI
> 2.0.  When both ->detect_ctx and ->detect are defined, the former takes
> precedence.  When ctx is NULL, locking is managed internally with EDEADLK
> retry.
> 
> Tested-by: Diederik de Haas <diederik@cknow-tech.com>
> Tested-by: Maud Spierings <maud_spierings@hotmail.com>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

while this looks sane to me, my drm insights are spotty, so I can
only provide the lighter

Acked-by: Heiko Stuebner <heiko@sntech.de>

Re: [PATCH v5 05/10] drm/bridge: dw-hdmi-qp: Add HDMI 2.0 SCDC scrambling and high TMDS clock ratio support

[Cristian Ciocaltea]

Hello Heiko,

Thanks for the quick reviews!

On 4/27/26 1:49 PM, Heiko Stuebner wrote:
> Am Sonntag, 26. April 2026, 02:20:17 Mitteleuropäische Sommerzeit schrieb Cristian Ciocaltea:
>> Enable HDMI 2.0 display modes (e.g. 4K@60Hz) by adding SCDC management
>> for the high TMDS clock ratio and scrambling, required when the TMDS
>> character rate exceeds the 340 MHz HDMI 1.4b limit.
>>
>> A periodic work item monitors the sink's scrambling status to recover
>> from sink-side resets.  On hotplug detect, if SCDC scrambling state is
>> out of sync with the driver, trigger a CRTC reset to re-establish the
>> link.
>>
>> Reject modes requiring TMDS rates above 600 MHz, as those fall in the
>> HDMI 2.1 FRL domain which is not supported. In no_hpd configurations,
>> further restrict to 340 MHz since SCDC requires a connected sink.
>>
>> Tested-by: Diederik de Haas <diederik@cknow-tech.com>
>> Tested-by: Maud Spierings <maud_spierings@hotmail.com>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 188 ++++++++++++++++++++++++---
>>  1 file changed, 172 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
>> index d649a1cf07f5..c482a8e7da25 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
>> @@ -2,6 +2,7 @@
>>  /*
>>   * Copyright (c) 2021-2022 Rockchip Electronics Co., Ltd.
>>   * Copyright (c) 2024 Collabora Ltd.
>> + * Copyright (c) 2025 Amazon.com, Inc. or its affiliates.
> 
> I have no real clue about the inner workings of hdmi, but that line
> does make me curious, because no part of the patch authorship does
> mention Amazon ;-) .

That was intentional: although the code was written by Collabora, the copyright
belongs to Amazon.

> Also I think "or it's affiliates" might be way too broad, because this
> can be essentially everyone. So noone in the future will know who to
> ask on copyright questions.
> 
> Similarly when _somebody_ comes forward with "I hold a copyright on this"
> no-one could verify this claim as well.
> 
> I somehow expect _one_ entity being specified, not possibly hundreds.

Hmm, I followed the wording already used elsewhere in the kernel tree:

$ git grep 'Copyright.*Amazon.*affiliates' | wc -l
93

There appears to be only a single instance that omits “affiliates”:

$ git grep 'Copyright.*Amazon' | grep -v affiliates
drivers/power/supply/max14656_charger_detector.c: * Copyright (C) Amazon Technologies Inc. All rights reserved.

Which was added nearly ten years ago, so I’m not sure it makes sense to adopt
that form now.

Actually, this seems to be fairly common among other vendors as well:

$ git grep 'Copyright.*affiliates' | wc -l
1014

Regards,
Cristian