[PATCH v2 0/7] drm: remove deprecated *_of_get_bridge() from non-OF drivers (fixes build regression)

[PATCH v2 0/7] drm: remove deprecated *_of_get_bridge() from non-OF drivers (fixes build regression)

[Luca Ceresoli]

After commit Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to
drm_panel.c") some drivers fail building:

  error: implicit declaration of function 'devm_drm_of_get_bridge'

This is because devm_drm_of_get_bridge() (and drmm_of_get_bridge()) have
been moved to drm-panel.h.

The affected drivers are those which:

 * can be built without CONFIG_OF, and
 * don't include drm_panel.h

The affected drivers are 3, fix them (patches 1-3) by replacing the
deprecated *_of_get_bridge() calls with of_drm_get_bridge_by_endpoint().

While there, do the same for all drivers which be built without CONFIG_OF,
even if they don't fail (patches 4-7).

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
Changes in v2:
- Fix bugs in patches 2,3,4
- Fix removed function name in patches 5,6
- Mention lkp reports in patches 2,3
- Add review tags on patches not modified since v1
- Link to v1: https://patch.msgid.link/20260929-drm-fix-of_get_bridge-build-regression-v1-0-ccb7e602daad@bootlin.com

---
Luca Ceresoli (7):
      drm/imx/lcdc: stop using deprecated devm_drm_of_get_bridge()
      drm: verisilicon: stop using deprecated devm_drm_of_get_bridge()
      drm/bridge: dw-mipi-dsi: stop using deprecated devm_drm_of_get_bridge()
      drm/bridge: dw-mipi-dsi2: stop using deprecated devm_drm_of_get_bridge()
      drm/vc4: dpi: stop using deprecated drmm_of_get_bridge()
      drm/vc4: dsi: stop using deprecated drmm_of_get_bridge()
      drm: renesas: shmobile: stop using deprecated devm_drm_of_get_bridge()

 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c     | 11 +++++------
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c    | 11 +++++------
 drivers/gpu/drm/imx/lcdc/imx-lcdc.c               |  4 ++--
 drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c |  5 ++---
 drivers/gpu/drm/vc4/vc4_dpi.c                     |  9 ++-------
 drivers/gpu/drm/vc4/vc4_dsi.c                     | 10 ++++------
 drivers/gpu/drm/verisilicon/vs_bridge.c           | 11 ++++++-----
 drivers/gpu/drm/verisilicon/vs_bridge.h           |  1 -
 8 files changed, 26 insertions(+), 36 deletions(-)
---
base-commit: 91ceac83e599c9d48da4c4d2d91410c588a215f7
change-id: 20260929-drm-fix-of_get_bridge-build-regression-98f22f8a1dcc

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

[PATCH v2 1/7] drm/imx/lcdc: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

devm_drm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put.

Fixes build failure when CONFIG_OF is disabled.

Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to drm_panel.c")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Link: https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/imx/lcdc/imx-lcdc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
index c67fe80b8115..805a659e3f85 100644
--- a/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
+++ b/drivers/gpu/drm/imx/lcdc/imx-lcdc.c
@@ -385,7 +385,6 @@ static int imx_lcdc_probe(struct platform_device *pdev)
 {
 	struct imx_lcdc *lcdc;
 	struct drm_device *drm;
-	struct drm_bridge *bridge;
 	int irq;
 	int ret;
 	struct device *dev = &pdev->dev;
@@ -401,7 +400,8 @@ static int imx_lcdc_probe(struct platform_device *pdev)
 	if (IS_ERR(lcdc->base))
 		return dev_err_probe(dev, PTR_ERR(lcdc->base), "Cannot get IO memory\n");
 
-	bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
+	struct drm_bridge *bridge __free(drm_bridge_put) =
+		of_drm_get_bridge_by_endpoint(dev->of_node, 0, 0);
 	if (IS_ERR(bridge))
 		return dev_err_probe(dev, PTR_ERR(bridge), "Failed to find bridge\n");
 

-- 
2.55.0

[PATCH v2 2/7] drm: verisilicon: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

devm_drm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put by using bridge.next_bridge.

Fixes build failure when CONFIG_OF is disabled.

Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to drm_panel.c")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609291109.OIsGTysr-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202609290408.BOs7sk55-lkp@intel.com/
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Changes in v2:
- fix bridge reference leak on attach error path
- mention lkp report
---
 drivers/gpu/drm/verisilicon/vs_bridge.c | 11 ++++++-----
 drivers/gpu/drm/verisilicon/vs_bridge.h |  1 -
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.c b/drivers/gpu/drm/verisilicon/vs_bridge.c
index dc7c85b07fe3..3a5091c0ac2c 100644
--- a/drivers/gpu/drm/verisilicon/vs_bridge.c
+++ b/drivers/gpu/drm/verisilicon/vs_bridge.c
@@ -29,7 +29,7 @@ static int vs_bridge_attach(struct drm_bridge *bridge,
 {
 	struct vs_bridge *vbridge = drm_bridge_to_vs_bridge(bridge);
 
-	return drm_bridge_attach(encoder, vbridge->next_bridge,
+	return drm_bridge_attach(encoder, vbridge->base.next_bridge,
 				 bridge, flags);
 }
 
@@ -303,8 +303,7 @@ struct vs_bridge *vs_bridge_init(struct drm_device *drm_dev,
 		return NULL;
 	}
 
-	next = devm_drm_of_get_bridge(drm_dev->dev, drm_dev->dev->of_node,
-				      output, intf);
+	next = of_drm_get_bridge_by_endpoint(drm_dev->dev->of_node, output, intf);
 	if (IS_ERR(next)) {
 		ret = PTR_ERR(next);
 		if (ret != -EPROBE_DEFER)
@@ -321,12 +320,14 @@ struct vs_bridge *vs_bridge_init(struct drm_device *drm_dev,
 
 	bridge = devm_drm_bridge_alloc(drm_dev->dev, struct vs_bridge, base,
 				       bridge_funcs);
-	if (IS_ERR(bridge))
+	if (IS_ERR(bridge)) {
+		drm_bridge_put(next);
 		return ERR_PTR(PTR_ERR(bridge));
+	}
 
 	bridge->crtc = crtc;
 	bridge->intf = intf;
-	bridge->next_bridge = next;
+	bridge->base.next_bridge = next;
 
 	if (intf == VSDC_OUTPUT_INTERFACE_DPI)
 		enctype = DRM_MODE_ENCODER_DPI;
diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.h b/drivers/gpu/drm/verisilicon/vs_bridge.h
index 70fee1749699..2b0ed94e4520 100644
--- a/drivers/gpu/drm/verisilicon/vs_bridge.h
+++ b/drivers/gpu/drm/verisilicon/vs_bridge.h
@@ -25,7 +25,6 @@ struct vs_bridge {
 	struct drm_connector *conn;
 
 	struct vs_crtc *crtc;
-	struct drm_bridge *next_bridge;
 	enum vs_bridge_output_interface intf;
 };
 

-- 
2.55.0

[PATCH v2 3/7] drm/bridge: dw-mipi-dsi: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

devm_drm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put by using bridge.next_bridge.

Fixes build failure when CONFIG_OF is disabled.

Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to drm_panel.c")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609291109.9RGna4XZ-lkp@intel.com/
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Changes in v2:
- fix bridge reference leak on attach error and detach paths
- mention lkp report
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 5dd475fcaacf..22d1b8cbe1d5 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -244,7 +244,6 @@ struct debugfs_entries {
 struct dw_mipi_dsi {
 	struct drm_bridge bridge;
 	struct mipi_dsi_host dsi_host;
-	struct drm_bridge *panel_bridge;
 	struct device *dev;
 	void __iomem *base;
 
@@ -333,12 +332,12 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
 	dsi->format = device->format;
 	dsi->mode_flags = device->mode_flags;
 
-	bridge = devm_drm_of_get_bridge(dsi->dev, dsi->dev->of_node, 1, 0);
+	bridge = of_drm_get_bridge_by_endpoint(dsi->dev->of_node, 1, 0);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);
 
 	bridge->pre_enable_prev_first = true;
-	dsi->panel_bridge = bridge;
+	dsi->bridge.next_bridge = bridge;
 
 	drm_bridge_add(&dsi->bridge);
 
@@ -352,6 +351,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
 
 err_remove_bridge:
 	drm_bridge_remove(&dsi->bridge);
+	drm_bridge_clear_and_put(&dsi->bridge.next_bridge);
 	return ret;
 }
 
@@ -368,9 +368,8 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
 			return ret;
 	}
 
-	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
-
 	drm_bridge_remove(&dsi->bridge);
+	drm_bridge_clear_and_put(&dsi->bridge.next_bridge);
 
 	return 0;
 }
@@ -1086,7 +1085,7 @@ static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge,
 	encoder->encoder_type = DRM_MODE_ENCODER_DSI;
 
 	/* Attach the panel-bridge to the dsi bridge */
-	return drm_bridge_attach(encoder, dsi->panel_bridge, bridge,
+	return drm_bridge_attach(encoder, dsi->bridge.next_bridge, bridge,
 				 flags);
 }
 

-- 
2.55.0

[PATCH v2 4/7] drm/bridge: dw-mipi-dsi2: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

devm_drm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put by using bridge.next_bridge.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Changes in v2:
- fix bridge reference leak on attach error and detach paths
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c
index 7fd2f1e60654..eb7d5713bd28 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c
@@ -192,7 +192,6 @@ struct cmd_header {
 struct dw_mipi_dsi2 {
 	struct drm_bridge bridge;
 	struct mipi_dsi_host dsi_host;
-	struct drm_bridge *panel_bridge;
 	struct device *dev;
 	struct regmap *regmap;
 	struct clk *pclk;
@@ -528,12 +527,12 @@ static int dw_mipi_dsi2_host_attach(struct mipi_dsi_host *host,
 	dsi2->format = device->format;
 	dsi2->mode_flags = device->mode_flags;
 
-	bridge = devm_drm_of_get_bridge(dsi2->dev, dsi2->dev->of_node, 1, 0);
+	bridge = of_drm_get_bridge_by_endpoint(dsi2->dev->of_node, 1, 0);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);
 
 	bridge->pre_enable_prev_first = true;
-	dsi2->panel_bridge = bridge;
+	dsi2->bridge.next_bridge = bridge;
 
 	drm_bridge_add(&dsi2->bridge);
 
@@ -547,6 +546,7 @@ static int dw_mipi_dsi2_host_attach(struct mipi_dsi_host *host,
 
 err_remove_bridge:
 	drm_bridge_remove(&dsi2->bridge);
+	drm_bridge_clear_and_put(&dsi2->bridge.next_bridge);
 	return ret;
 }
 
@@ -564,8 +564,7 @@ static int dw_mipi_dsi2_host_detach(struct mipi_dsi_host *host,
 	}
 
 	drm_bridge_remove(&dsi2->bridge);
-
-	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
+	drm_bridge_clear_and_put(&dsi2->bridge.next_bridge);
 
 	return 0;
 }
@@ -884,7 +883,7 @@ static int dw_mipi_dsi2_bridge_attach(struct drm_bridge *bridge,
 	encoder->encoder_type = DRM_MODE_ENCODER_DSI;
 
 	/* Attach the panel-bridge to the dsi bridge */
-	return drm_bridge_attach(encoder, dsi2->panel_bridge, bridge,
+	return drm_bridge_attach(encoder, dsi2->bridge.next_bridge, bridge,
 				 flags);
 }
 

-- 
2.55.0

[PATCH v2 5/7] drm/vc4: dpi: stop using deprecated drmm_of_get_bridge()

[Luca Ceresoli]

drmm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put.

drm_panel.h becomes unused, drop the include.

Also remove a comment that is now obvious: now panels are just bridges.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/vc4/vc4_dpi.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c
index 53f36626a50d..5060eb463704 100644
--- a/drivers/gpu/drm/vc4/vc4_dpi.c
+++ b/drivers/gpu/drm/vc4/vc4_dpi.c
@@ -16,7 +16,6 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_of.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
@@ -279,16 +278,12 @@ static const struct of_device_id vc4_dpi_dt_match[] = {
 	{}
 };
 
-/* Sets up the next link in the display chain, whether it's a panel or
- * a bridge.
- */
 static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
 {
-	struct drm_device *drm = dpi->encoder.base.dev;
 	struct device *dev = &dpi->pdev->dev;
-	struct drm_bridge *bridge;
 
-	bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
+	struct drm_bridge *bridge __free(drm_bridge_put) =
+		of_drm_get_bridge_by_endpoint(dev->of_node, 0, 0);
 	if (IS_ERR(bridge)) {
 		/* If nothing was connected in the DT, that's not an
 		 * error.

-- 
2.55.0

[PATCH v2 6/7] drm/vc4: dsi: stop using deprecated drmm_of_get_bridge()

[Luca Ceresoli]

drmm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put by using bridge.next_bridge.

drm_panel.h becomes unused, drop the include.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 0148f2befed1..30598738cfcf 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -35,7 +35,6 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
@@ -555,7 +554,6 @@ struct vc4_dsi {
 
 	struct platform_device *pdev;
 
-	struct drm_bridge *out_bridge;
 	struct drm_bridge bridge;
 
 	void __iomem *regs;
@@ -1165,7 +1163,7 @@ static int vc4_dsi_bridge_attach(struct drm_bridge *bridge,
 	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
 
 	/* Attach the panel or bridge to the dsi bridge */
-	return drm_bridge_attach(encoder, dsi->out_bridge,
+	return drm_bridge_attach(encoder, dsi->bridge.next_bridge,
 				 &dsi->bridge, flags);
 }
 
@@ -1749,9 +1747,9 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
-	dsi->out_bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
-	if (IS_ERR(dsi->out_bridge))
-		return PTR_ERR(dsi->out_bridge);
+	dsi->bridge.next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 0, 0);
+	if (IS_ERR(dsi->bridge.next_bridge))
+		return PTR_ERR(dsi->bridge.next_bridge);
 
 	/* The esc clock rate is supposed to always be 100Mhz. */
 	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);

-- 
2.55.0

[PATCH v2 7/7] drm: renesas: shmobile: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

devm_drm_of_get_bridge() is deprecated, switch to
of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
a refcounted bridge, ensure it is put.

drm_panel.h becomes unused, drop the include.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
index 328a36215e39..51bae2008cc6 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
@@ -28,7 +28,6 @@
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_modeset_helper_vtables.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -447,7 +446,6 @@ static const struct drm_encoder_funcs shmob_encoder_funcs = {
 int shmob_drm_encoder_create(struct shmob_drm_device *sdev)
 {
 	struct drm_encoder *encoder = &sdev->encoder;
-	struct drm_bridge *bridge;
 	int ret;
 
 	encoder->possible_crtcs = 1;
@@ -463,7 +461,8 @@ int shmob_drm_encoder_create(struct shmob_drm_device *sdev)
 	}
 
 	/* Create a panel bridge */
-	bridge = devm_drm_of_get_bridge(sdev->dev, sdev->dev->of_node, 0, 0);
+	struct drm_bridge *bridge __free(drm_bridge_put) =
+		of_drm_get_bridge_by_endpoint(sdev->dev->of_node, 0, 0);
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);
 

-- 
2.55.0

Re: [PATCH v2 2/7] drm: verisilicon: stop using deprecated devm_drm_of_get_bridge()

[Icenowy Zheng]

在 2026-09-29二的 15:39 +0200，Luca Ceresoli写道：
> devm_drm_of_get_bridge() is deprecated, switch to
> of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint()
> returns
> a refcounted bridge, ensure it is put by using bridge.next_bridge.
> 
> Fixes build failure when CONFIG_OF is disabled.
> 
> Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to
> drm_panel.c")
> Reported-by: Arnd Bergmann <arnd@kernel.org>
> Closes:
> https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org
> Reported-by: kernel test robot <lkp@intel.com>
> Closes:
> https://lore.kernel.org/oe-kbuild-all/202609291109.OIsGTysr-lkp@intel.com/
> Closes:
> https://lore.kernel.org/oe-kbuild-all/202609290408.BOs7sk55-lkp@intel.com/
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Checked the code in drm_bridge.c, and it looks like the lifetime of
next_bridge should be indirectly managed by devm when
devm_drm_bridge_alloc() successes and the next_bridge field assigned,
so the only explicit put needed here should be in the alloc failure
path.

Patch is:

```
Reviewed-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
```

> 
> ---
> 
> Changes in v2:
> - fix bridge reference leak on attach error path

It should be `bridge alloc error` instead of `attach error`, but I
don't know how to correct the error in the changelog, and anyway it
won't be part of the final commit.

Thanks,
Icenowy

> - mention lkp report
> ---
>  drivers/gpu/drm/verisilicon/vs_bridge.c | 11 ++++++-----
>  drivers/gpu/drm/verisilicon/vs_bridge.h |  1 -
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.c
> b/drivers/gpu/drm/verisilicon/vs_bridge.c
> index dc7c85b07fe3..3a5091c0ac2c 100644
> --- a/drivers/gpu/drm/verisilicon/vs_bridge.c
> +++ b/drivers/gpu/drm/verisilicon/vs_bridge.c
> @@ -29,7 +29,7 @@ static int vs_bridge_attach(struct drm_bridge
> *bridge,
>  {
>  	struct vs_bridge *vbridge = drm_bridge_to_vs_bridge(bridge);
>  
> -	return drm_bridge_attach(encoder, vbridge->next_bridge,
> +	return drm_bridge_attach(encoder, vbridge->base.next_bridge,
>  				 bridge, flags);
>  }
>  
> @@ -303,8 +303,7 @@ struct vs_bridge *vs_bridge_init(struct
> drm_device *drm_dev,
>  		return NULL;
>  	}
>  
> -	next = devm_drm_of_get_bridge(drm_dev->dev, drm_dev->dev-
> >of_node,
> -				      output, intf);
> +	next = of_drm_get_bridge_by_endpoint(drm_dev->dev->of_node,
> output, intf);
>  	if (IS_ERR(next)) {
>  		ret = PTR_ERR(next);
>  		if (ret != -EPROBE_DEFER)
> @@ -321,12 +320,14 @@ struct vs_bridge *vs_bridge_init(struct
> drm_device *drm_dev,
>  
>  	bridge = devm_drm_bridge_alloc(drm_dev->dev, struct
> vs_bridge, base,
>  				       bridge_funcs);
> -	if (IS_ERR(bridge))
> +	if (IS_ERR(bridge)) {
> +		drm_bridge_put(next);
>  		return ERR_PTR(PTR_ERR(bridge));
> +	}
>  
>  	bridge->crtc = crtc;
>  	bridge->intf = intf;
> -	bridge->next_bridge = next;
> +	bridge->base.next_bridge = next;
>  
>  	if (intf == VSDC_OUTPUT_INTERFACE_DPI)
>  		enctype = DRM_MODE_ENCODER_DPI;
> diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.h
> b/drivers/gpu/drm/verisilicon/vs_bridge.h
> index 70fee1749699..2b0ed94e4520 100644
> --- a/drivers/gpu/drm/verisilicon/vs_bridge.h
> +++ b/drivers/gpu/drm/verisilicon/vs_bridge.h
> @@ -25,7 +25,6 @@ struct vs_bridge {
>  	struct drm_connector *conn;
>  
>  	struct vs_crtc *crtc;
> -	struct drm_bridge *next_bridge;
>  	enum vs_bridge_output_interface intf;
>  };
>  

Re: [PATCH v2 2/7] drm: verisilicon: stop using deprecated devm_drm_of_get_bridge()

[Luca Ceresoli]

Hello,

On Tue Sep 29, 2026 at 4:42 PM CEST, Icenowy Zheng wrote:
> 在 2026-09-29二的 15:39 +0200，Luca Ceresoli写道：
>> devm_drm_of_get_bridge() is deprecated, switch to
>> of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint()
>> returns
>> a refcounted bridge, ensure it is put by using bridge.next_bridge.
>>
>> Fixes build failure when CONFIG_OF is disabled.
>>
>> Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to
>> drm_panel.c")
>> Reported-by: Arnd Bergmann <arnd@kernel.org>
>> Closes:
>> https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org
>> Reported-by: kernel test robot <lkp@intel.com>
>> Closes:
>> https://lore.kernel.org/oe-kbuild-all/202609291109.OIsGTysr-lkp@intel.com/
>> Closes:
>> https://lore.kernel.org/oe-kbuild-all/202609290408.BOs7sk55-lkp@intel.com/
>> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>
> Checked the code in drm_bridge.c, and it looks like the lifetime of
> next_bridge should be indirectly managed by devm when
> devm_drm_bridge_alloc() successes and the next_bridge field assigned,
> so the only explicit put needed here should be in the alloc failure
> path.

Exactly.

I think vs_bridge_init() could be simplified a bit by moving the 'next =
...;' statement (with error management trailer) to after
devm_drm_bridge_alloc. This would avoid the explicit drm_bridge_put() call
added by this patch.

However for this regression fix I preferred to keep the diff minimal. The
cleanup mentioned above can be done later.

> Reviewed-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>

Thanks for reviewing!

>> Changes in v2:
>> - fix bridge reference leak on attach error path
>
> It should be `bridge alloc error` instead of `attach error`, but I
> don't know how to correct the error in the changelog, and anyway it
> won't be part of the final commit.

Ah, right, that's a copy-paste leftover. It's correct that it won't appear
in the commit, so I won't sent a new iteration for this.

Luca

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