[PATCH 0/6] drm/bridge: convert users of of_drm_find_bridge(), part 3

[PATCH 0/6] drm/bridge: convert users of of_drm_find_bridge(), part 3

[Luca Ceresoli]

This series converts many DRM drivers from the now deprecated
of_drm_find_bridge() to its replacement of_drm_find_and_get_bridge() which
allows correct bridge refcounting. Where applicable it also converts
per-driver "next_bridge" pointers to the unified drm_bridge::next_bridge
which puts the reference automatically on bridge deallocation.

This is part of the work to support hotplug of DRM bridges. The grand plan
was discussed in [0].

Here's the work breakdown (➜ marks the current series):

 1. ➜ add refcounting to DRM bridges struct drm_bridge,
      based on devm_drm_bridge_alloc()
    A. ✔ add new alloc API and refcounting (v6.16)
    B. ✔ convert all bridge drivers to new API (v6.17)
    C. ✔ kunit tests (v6.17)
    D. ✔ add get/put to drm_bridge_add/remove() + attach/detach()
         and warn on old allocation pattern (v6.17)
    E. ➜ add get/put on drm_bridge accessors
       1. ✔ drm_bridge_chain_get_first_bridge(), add cleanup action (v6.18)
       2. ✔ drm_bridge_get_prev_bridge() (v6.18)
       3. ✔ drm_bridge_get_next_bridge() (v6.19)
       4. ✔ drm_for_each_bridge_in_chain() (v6.19)
       5. ✔ drm_bridge_connector_init (v6.19)
       6. … protect encoder bridge chain with a mutex
       7. ➜ of_drm_find_bridge
          a. ✔… add of_drm_get_bridge(), convert basic direct users
	        (v6.20?, one driver still pending)
	  b. … convert direct of_drm_get_bridge() users, part 2
	  c. ➜ convert direct of_drm_get_bridge() users, part 3
	  d.   convert direct of_drm_get_bridge() users, part 4
	  e.   convert bridge-only drm_of_find_panel_or_bridge() users
       8. drm_of_find_panel_or_bridge, *_of_get_bridge
       9. ✔ enforce drm_bridge_add before drm_bridge_attach (v6.19)
    F. ✔ debugfs improvements
       1. ✔ add top-level 'bridges' file (v6.16)
       2. ✔ show refcount and list lingering bridges (v6.19)
 2. … handle gracefully atomic updates during bridge removal
    A. ✔ Add drm_dev_enter/exit() to protect device resources (v6.20?)
    B. … protect private_obj removal from list
 3. … DSI host-device driver interaction
 4. ✔ removing the need for the "always-disconnected" connector
 5. finish the hotplug bridge work, moving code to the core and potentially
    removing the hotplug-bridge itself (this needs to be clarified as
    points 1-3 are developed)

[0] https://lore.kernel.org/lkml/20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com/#t

This work is a continuation of the work to correctly handle bridge
refcounting for existing of_drm_find_bridge(). The ground work is in:

 - commit 293a8fd7721a ("drm/bridge: add of_drm_find_and_get_bridge()")
 - commit 9da0e06abda8 ("drm/bridge: deprecate of_drm_find_bridge()")
 - commit 3fdeae134ba9 ("drm/bridge: add next_bridge pointer to struct drm_bridge")

The whole conversion is split in multiple series to make the review process
a bit smoother:

 - Part 2: mostly drivers in drivers/gpu/drm/bridge [2]
 - Part 3: other drivers, low-medium complexity [this series]
 - Part 4: other drivers, complex (not sent yet)

[2] https://lore.kernel.org/all/20260107-drm-bridge-alloc-getput-drm_of_find_bridge-2-v1-0-283d7bba061a@bootlin.com/

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
Luca Ceresoli (6):
      drm/bridge: dw-hdmi: convert to of_drm_find_and_get_bridge()
      drm/meson/dw-hdmi: convert to of_drm_find_and_get_bridge()
      drm/imx/dw-hdmi: convert to of_drm_find_and_get_bridge()
      drm/mediatek: mtk_hdmi*: convert to of_drm_find_and_get_bridge()
      drm/exynos: hdmi: convert to of_drm_find_and_get_bridge()
      drm: rcar-du: lvds: convert to of_drm_find_and_get_bridge()

 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c   |  7 +++----
 drivers/gpu/drm/exynos/exynos_hdmi.c        |  4 +++-
 drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c     |  3 ++-
 drivers/gpu/drm/mediatek/mtk_hdmi.c         |  4 ++--
 drivers/gpu/drm/mediatek/mtk_hdmi_common.c  |  4 ++--
 drivers/gpu/drm/mediatek/mtk_hdmi_common.h  |  1 -
 drivers/gpu/drm/mediatek/mtk_hdmi_v2.c      |  4 ++--
 drivers/gpu/drm/meson/meson_dw_hdmi.c       |  6 +++++-
 drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c | 10 +++++++++-
 9 files changed, 28 insertions(+), 15 deletions(-)
---
base-commit: faeb4ff6d6e41c42741fd1df8e1d0b80f9452403
change-id: 20260107-drm-bridge-alloc-getput-drm_of_find_bridge-3-4f997ea7c79f

Best regards,
-- 
Luca Ceresoli <luca.ceresoli@bootlin.com>

[PATCH 1/6] drm/bridge: dw-hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done by using the drm_bridge::next_bridge pointer.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 3b77e73ac0ea..ee88c0e793b0 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -132,7 +132,6 @@ struct dw_hdmi_phy_data {
 struct dw_hdmi {
 	struct drm_connector connector;
 	struct drm_bridge bridge;
-	struct drm_bridge *next_bridge;
 
 	unsigned int version;
 
@@ -2912,7 +2911,7 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge,
 	struct dw_hdmi *hdmi = bridge->driver_private;
 
 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
-		return drm_bridge_attach(encoder, hdmi->next_bridge,
+		return drm_bridge_attach(encoder, hdmi->bridge.next_bridge,
 					 bridge, flags);
 
 	return dw_hdmi_connector_create(hdmi);
@@ -3318,9 +3317,9 @@ static int dw_hdmi_parse_dt(struct dw_hdmi *hdmi)
 	if (!remote)
 		return -ENODEV;
 
-	hdmi->next_bridge = of_drm_find_bridge(remote);
+	hdmi->bridge.next_bridge = of_drm_find_and_get_bridge(remote);
 	of_node_put(remote);
-	if (!hdmi->next_bridge)
+	if (!hdmi->bridge.next_bridge)
 		return -EPROBE_DEFER;
 
 	return 0;

-- 
2.52.0

[PATCH 2/6] drm/meson/dw-hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

dw_hdmi->bridge is used only in dw_hdmi_top_thread_irq(), so in order to
avoid potential use-after-free ensure the irq is freed before putting the
dw_hdmi->bridge reference.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 0d7c68b29dff..fef1702acb14 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -778,7 +778,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 	if (IS_ERR(meson_dw_hdmi->hdmi))
 		return PTR_ERR(meson_dw_hdmi->hdmi);
 
-	meson_dw_hdmi->bridge = of_drm_find_bridge(pdev->dev.of_node);
+	meson_dw_hdmi->bridge = of_drm_find_and_get_bridge(pdev->dev.of_node);
 
 	DRM_DEBUG_DRIVER("HDMI controller initialized\n");
 
@@ -789,8 +789,12 @@ static void meson_dw_hdmi_unbind(struct device *dev, struct device *master,
 				   void *data)
 {
 	struct meson_dw_hdmi *meson_dw_hdmi = dev_get_drvdata(dev);
+	struct platform_device *pdev = to_platform_device(dev);
+	int irq = platform_get_irq(pdev, 0);
 
+	devm_free_irq(dev, irq, meson_dw_hdmi);
 	dw_hdmi_unbind(meson_dw_hdmi->hdmi);
+	drm_bridge_put(meson_dw_hdmi->bridge);
 }
 
 static const struct component_ops meson_dw_hdmi_ops = {

-- 
2.52.0

[PATCH 3/6] drm/imx/dw-hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
index 07e5f96202d4..95f629d97bce 100644
--- a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
+++ b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
@@ -241,7 +241,7 @@ static int dw_hdmi_imx_probe(struct platform_device *pdev)
 	if (IS_ERR(hdmi->hdmi))
 		return PTR_ERR(hdmi->hdmi);
 
-	hdmi->bridge = of_drm_find_bridge(np);
+	hdmi->bridge = of_drm_find_and_get_bridge(np);
 	if (!hdmi->bridge) {
 		dev_err(hdmi->dev, "Unable to find bridge\n");
 		dw_hdmi_remove(hdmi->hdmi);
@@ -261,6 +261,7 @@ static void dw_hdmi_imx_remove(struct platform_device *pdev)
 
 	component_del(&pdev->dev, &dw_hdmi_imx_ops);
 	dw_hdmi_remove(hdmi->hdmi);
+	drm_bridge_put(hdmi->bridge);
 }
 
 static struct platform_driver dw_hdmi_imx_platform_driver = {

-- 
2.52.0

[PATCH 4/6] drm/mediatek: mtk_hdmi*: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done by using the drm_bridge::next_bridge pointer.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/mediatek/mtk_hdmi.c        | 4 ++--
 drivers/gpu/drm/mediatek/mtk_hdmi_common.c | 4 ++--
 drivers/gpu/drm/mediatek/mtk_hdmi_common.h | 1 -
 drivers/gpu/drm/mediatek/mtk_hdmi_v2.c     | 4 ++--
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 0face4dcaa36..1ea259854780 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -986,8 +986,8 @@ static int mtk_hdmi_bridge_attach(struct drm_bridge *bridge,
 		return -EINVAL;
 	}
 
-	if (hdmi->next_bridge) {
-		ret = drm_bridge_attach(encoder, hdmi->next_bridge,
+	if (hdmi->bridge.next_bridge) {
+		ret = drm_bridge_attach(encoder, hdmi->bridge.next_bridge,
 					bridge, flags);
 		if (ret)
 			return ret;
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_common.c b/drivers/gpu/drm/mediatek/mtk_hdmi_common.c
index e78eb0876f16..40ded86dbea3 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi_common.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi_common.c
@@ -315,8 +315,8 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi, struct platform_device
 		return -EINVAL;
 
 	if (!of_device_is_compatible(remote, "hdmi-connector")) {
-		hdmi->next_bridge = of_drm_find_bridge(remote);
-		if (!hdmi->next_bridge) {
+		hdmi->bridge.next_bridge = of_drm_find_and_get_bridge(remote);
+		if (!hdmi->bridge.next_bridge) {
 			dev_err(dev, "Waiting for external bridge\n");
 			of_node_put(remote);
 			return -EPROBE_DEFER;
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_common.h b/drivers/gpu/drm/mediatek/mtk_hdmi_common.h
index de5e064585f8..cace3c5dc067 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi_common.h
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi_common.h
@@ -150,7 +150,6 @@ struct mtk_hdmi_conf {
 
 struct mtk_hdmi {
 	struct drm_bridge bridge;
-	struct drm_bridge *next_bridge;
 	struct drm_connector *curr_conn;/* current connector (only valid when 'enabled') */
 	struct device *dev;
 	const struct mtk_hdmi_conf *conf;
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
index c272e1e74b7d..2adeece499b6 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
@@ -940,8 +940,8 @@ static int mtk_hdmi_v2_bridge_attach(struct drm_bridge *bridge,
 		DRM_ERROR("The flag DRM_BRIDGE_ATTACH_NO_CONNECTOR must be supplied\n");
 		return -EINVAL;
 	}
-	if (hdmi->next_bridge) {
-		ret = drm_bridge_attach(encoder, hdmi->next_bridge, bridge, flags);
+	if (hdmi->bridge.next_bridge) {
+		ret = drm_bridge_attach(encoder, hdmi->bridge.next_bridge, bridge, flags);
 		if (ret)
 			return ret;
 	}

-- 
2.52.0

[PATCH 5/6] drm/exynos: hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/exynos/exynos_hdmi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 01813e11e6c6..bfcf2fa62fe1 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1779,7 +1779,7 @@ static int hdmi_bridge_init(struct hdmi_context *hdata)
 		return -EINVAL;
 	}
 
-	hdata->bridge = of_drm_find_bridge(np);
+	hdata->bridge = of_drm_find_and_get_bridge(np);
 	of_node_put(np);
 
 	if (!hdata->bridge)
@@ -2096,6 +2096,8 @@ static void hdmi_remove(struct platform_device *pdev)
 
 	put_device(&hdata->ddc_adpt->dev);
 
+	drm_bridge_put(hdata->bridge);
+
 	mutex_destroy(&hdata->mutex);
 }
 

-- 
2.52.0

[PATCH 6/6] drm: rcar-du: lvds: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

Since the companion bridge pointer is used by .atomic_enable, putting its
reference in the remove function would be dangerous. Use .destroy to put it
on final deallocation.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c b/drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c
index 001b3543924a..227818e37390 100644
--- a/drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c
@@ -633,6 +633,13 @@ static bool rcar_lvds_mode_fixup(struct drm_bridge *bridge,
 	return true;
 }
 
+static void rcar_lvds_destroy(struct drm_bridge *bridge)
+{
+	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
+
+	drm_bridge_put(lvds->companion);
+}
+
 static int rcar_lvds_attach(struct drm_bridge *bridge,
 			    struct drm_encoder *encoder,
 			    enum drm_bridge_attach_flags flags)
@@ -648,6 +655,7 @@ static int rcar_lvds_attach(struct drm_bridge *bridge,
 
 static const struct drm_bridge_funcs rcar_lvds_bridge_ops = {
 	.attach = rcar_lvds_attach,
+	.destroy = rcar_lvds_destroy,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 	.atomic_reset = drm_atomic_helper_bridge_reset,
@@ -740,7 +748,7 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 		goto done;
 	}
 
-	lvds->companion = of_drm_find_bridge(companion);
+	lvds->companion = of_drm_find_and_get_bridge(companion);
 	if (!lvds->companion) {
 		ret = -EPROBE_DEFER;
 		goto done;

-- 
2.52.0

Re: [PATCH 3/6] drm/imx/dw-hdmi: convert to of_drm_find_and_get_bridge()

[Philipp Zabel]

On Mi, 2026-01-07 at 17:22 +0100, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> ---
>  drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
> index 07e5f96202d4..95f629d97bce 100644
> --- a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
> +++ b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
> @@ -241,7 +241,7 @@ static int dw_hdmi_imx_probe(struct platform_device *pdev)
>  	if (IS_ERR(hdmi->hdmi))
>  		return PTR_ERR(hdmi->hdmi);
>  
> -	hdmi->bridge = of_drm_find_bridge(np);
> +	hdmi->bridge = of_drm_find_and_get_bridge(np);
>  	if (!hdmi->bridge) {
>  		dev_err(hdmi->dev, "Unable to find bridge\n");
>  		dw_hdmi_remove(hdmi->hdmi);

The component_add() error path below this is missing a
drm_bridge_put().

regards
Philipp

Re: [PATCH 3/6] drm/imx/dw-hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

Hello Philipp,

On Wed Jan 7, 2026 at 5:34 PM CET, Philipp Zabel wrote:
> On Mi, 2026-01-07 at 17:22 +0100, Luca Ceresoli wrote:
>> of_drm_find_bridge() is deprecated. Move to its replacement
>> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
>> is put when done.
>>
>> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>> ---
>>  drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
>> index 07e5f96202d4..95f629d97bce 100644
>> --- a/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
>> +++ b/drivers/gpu/drm/imx/ipuv3/dw_hdmi-imx.c
>> @@ -241,7 +241,7 @@ static int dw_hdmi_imx_probe(struct platform_device *pdev)
>>  	if (IS_ERR(hdmi->hdmi))
>>  		return PTR_ERR(hdmi->hdmi);
>>
>> -	hdmi->bridge = of_drm_find_bridge(np);
>> +	hdmi->bridge = of_drm_find_and_get_bridge(np);
>>  	if (!hdmi->bridge) {
>>  		dev_err(hdmi->dev, "Unable to find bridge\n");
>>  		dw_hdmi_remove(hdmi->hdmi);
>
> The component_add() error path below this is missing a
> drm_bridge_put().

Right! Thanks for reviewing, fix queued for v2.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH 1/6] drm/bridge: dw-hdmi: convert to of_drm_find_and_get_bridge()

[Maxime Ripard]

On Wed, 7 Jan 2026 17:21:59 +0100, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done by using the drm_bridge::next_bridge pointer.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH 2/6] drm/meson/dw-hdmi: convert to of_drm_find_and_get_bridge()

[Maxime Ripard]

On Wed, 7 Jan 2026 17:22:00 +0100, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done.
> 
> dw_hdmi->bridge is used only in dw_hdmi_top_thread_irq(), so in order to
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH 4/6] drm/mediatek: mtk_hdmi*: convert to of_drm_find_and_get_bridge()

[Maxime Ripard]

On Wed, 7 Jan 2026 17:22:02 +0100, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done by using the drm_bridge::next_bridge pointer.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH 5/6] drm/exynos: hdmi: convert to of_drm_find_and_get_bridge()

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 1237 bytes --]

On Wed, Jan 07, 2026 at 05:22:03PM +0100, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Why can't we use next_bridge for this one?

> ---
>  drivers/gpu/drm/exynos/exynos_hdmi.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
> index 01813e11e6c6..bfcf2fa62fe1 100644
> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
> @@ -1779,7 +1779,7 @@ static int hdmi_bridge_init(struct hdmi_context *hdata)
>  		return -EINVAL;
>  	}
>  
> -	hdata->bridge = of_drm_find_bridge(np);
> +	hdata->bridge = of_drm_find_and_get_bridge(np);
>  	of_node_put(np);
>  
>  	if (!hdata->bridge)
> @@ -2096,6 +2096,8 @@ static void hdmi_remove(struct platform_device *pdev)
>  
>  	put_device(&hdata->ddc_adpt->dev);
>  
> +	drm_bridge_put(hdata->bridge);
> +
>  	mutex_destroy(&hdata->mutex);
>  }

Same story than in your part 2 series, it should be dropped in destroy.

Maxime

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Re: [PATCH 5/6] drm/exynos: hdmi: convert to of_drm_find_and_get_bridge()

[Marek Szyprowski]

On 07.01.2026 17:22, Luca Ceresoli wrote:
> of_drm_find_bridge() is deprecated. Move to its replacement
> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
> is put when done.
>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> ---
>   drivers/gpu/drm/exynos/exynos_hdmi.c | 4 +++-

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
> index 01813e11e6c6..bfcf2fa62fe1 100644
> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
> @@ -1779,7 +1779,7 @@ static int hdmi_bridge_init(struct hdmi_context *hdata)
>   		return -EINVAL;
>   	}
>   
> -	hdata->bridge = of_drm_find_bridge(np);
> +	hdata->bridge = of_drm_find_and_get_bridge(np);
>   	of_node_put(np);
>   
>   	if (!hdata->bridge)
> @@ -2096,6 +2096,8 @@ static void hdmi_remove(struct platform_device *pdev)
>   
>   	put_device(&hdata->ddc_adpt->dev);
>   
> +	drm_bridge_put(hdata->bridge);
> +
>   	mutex_destroy(&hdata->mutex);
>   }
>   
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH 5/6] drm/exynos: hdmi: convert to of_drm_find_and_get_bridge()

[Luca Ceresoli]

Hi Maxime,

On Thu Jan 8, 2026 at 9:14 AM CET, Maxime Ripard wrote:
> On Wed, Jan 07, 2026 at 05:22:03PM +0100, Luca Ceresoli wrote:
>> of_drm_find_bridge() is deprecated. Move to its replacement
>> of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
>> is put when done.
>>
>> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>
> Why can't we use next_bridge for this one?

Because this device is not a bridge, so we have no struct drm_bridge.

>> ---
>>  drivers/gpu/drm/exynos/exynos_hdmi.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
>> index 01813e11e6c6..bfcf2fa62fe1 100644
>> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
>> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
>> @@ -1779,7 +1779,7 @@ static int hdmi_bridge_init(struct hdmi_context *hdata)
>>  		return -EINVAL;
>>  	}
>>
>> -	hdata->bridge = of_drm_find_bridge(np);
>> +	hdata->bridge = of_drm_find_and_get_bridge(np);
>>  	of_node_put(np);
>>
>>  	if (!hdata->bridge)
>> @@ -2096,6 +2096,8 @@ static void hdmi_remove(struct platform_device *pdev)
>>
>>  	put_device(&hdata->ddc_adpt->dev);
>>
>> +	drm_bridge_put(hdata->bridge);
>> +
>>  	mutex_destroy(&hdata->mutex);
>>  }
>
> Same story than in your part 2 series, it should be dropped in destroy.

hdata->bridge is only used for drm_bridge_attach(), it won't be referenced
after that. So this is safe, unless I'm missing something.

Also as we don't have a struct drm_bridge (as mentioned above) we have no
bridge destroy. We have the encoder destroy, but that will never be called
on bridge hotplug.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com