Hello Sebastian,

At 2026-08-07 01:02:08, "Sebastian Reichel" <[email protected]> 
wrote:
>Currently the Synopsys DesignWare DP controller driver's bind function
>requests lots of resources using device managed functions. These are
>free'd on driver removal instead of at unbind time. Fix this discrepancy
>by introducing a new probe helper function and moving over the whole
>bind function. This results in a fully functional DRM bridge once probe
>succeeded. The only thing still happening when the component is bound
>is the bridge attachment, which requires the encoder.
>
>The interrupt is kept disabled while the bridge is detached to ensure no
>spurious interrupts can arrive as the interrupt handler triggers a
>worker, which accesses the DRM device.
>
>Fixes: 86eecc3a9c2e ("drm/bridge: synopsys: Add DW DPTX Controller support 
>library")
>Reported-by: Sashiko <[email protected]>
>Signed-off-by: Sebastian Reichel <[email protected]>

   Acked-by: Andy Yan <[email protected]>

>---
> drivers/gpu/drm/bridge/synopsys/dw-dp.c   | 73 ++++++++++++++++---------------
> drivers/gpu/drm/rockchip/dw_dp-rockchip.c | 53 ++++++++++++----------
> include/drm/bridge/dw_dp.h                |  5 ++-
> 3 files changed, 72 insertions(+), 59 deletions(-)
>
>diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c 
>b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
>index 60feb3d1e14b..d7945f7fe9f0 100644
>--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
>+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
>@@ -1827,16 +1827,22 @@ static int dw_dp_bridge_attach(struct drm_bridge 
>*bridge,
>       dp->aux.transfer = dw_dp_aux_transfer;
> 
>       ret = drm_dp_aux_register(&dp->aux);
>-      if (ret)
>+      if (ret) {
>               dev_err(dev, "Aux register failed: %d\n", ret);
>+              return ret;
>+      }
> 
>-      return ret;
>+      enable_irq(dp->irq);
>+
>+      return 0;
> }
> 
> static void dw_dp_bridge_detach(struct drm_bridge *bridge)
> {
>       struct dw_dp *dp = bridge_to_dp(bridge);
> 
>+      disable_irq(dp->irq);
>+      cancel_work_sync(&dp->hpd_work);
>       drm_dp_aux_unregister(&dp->aux);
> }
> 
>@@ -1982,6 +1988,18 @@ static const struct regmap_config dw_dp_regmap_config = 
>{
>       .rd_table = &dw_dp_readable_table,
> };
> 
>+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder)
>+{
>+      return drm_bridge_attach(encoder, &dp->bridge, NULL, 
>DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>+}
>+EXPORT_SYMBOL_GPL(dw_dp_bind);
>+
>+void dw_dp_unbind(struct dw_dp *dp)
>+{
>+      /* nothing to do as bridge is detached automatically */
>+}
>+EXPORT_SYMBOL_GPL(dw_dp_unbind);
>+
> static void dw_dp_phy_exit(void *data)
> {
>       struct dw_dp *dp = data;
>@@ -1989,13 +2007,12 @@ static void dw_dp_phy_exit(void *data)
>       phy_exit(dp->phy);
> }
> 
>-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
>-                       const struct dw_dp_plat_data *plat_data)
>+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct 
>dw_dp_plat_data *plat_data)
> {
>-      struct platform_device *pdev = to_platform_device(dev);
>-      struct dw_dp *dp;
>+      struct device *dev = &pdev->dev;
>       struct drm_bridge *bridge;
>       void __iomem *res;
>+      struct dw_dp *dp;
>       int ret;
> 
>       dp = devm_drm_bridge_alloc(dev, struct dw_dp, bridge, 
> &dw_dp_bridge_funcs);
>@@ -2004,9 +2021,8 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct 
>drm_encoder *encoder,
> 
>       dp->dev = dev;
>       dp->pixel_mode = plat_data->pixel_mode;
>-
>       dp->plat_data.max_link_rate = plat_data->max_link_rate;
>-      bridge = &dp->bridge;
>+
>       mutex_init(&dp->irq_lock);
>       INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
>       init_completion(&dp->complete);
>@@ -2063,18 +2079,14 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct 
>drm_encoder *encoder,
>               return ERR_CAST(dp->rstc);
>       }
> 
>-      bridge->of_node = dev->of_node;
>-      bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | 
>DRM_BRIDGE_OP_HPD;
>-      bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
>-      bridge->ycbcr_420_allowed = true;
>-
>-      ret = devm_drm_bridge_add(dev, bridge);
>-      if (ret)
>-              return ERR_PTR(ret);
>+      dp->irq = platform_get_irq(pdev, 0);
>+      if (dp->irq < 0)
>+              return ERR_PTR(dp->irq);
> 
>-      ret = drm_bridge_attach(encoder, bridge, NULL, 
>DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>+      ret = devm_request_threaded_irq(dev, dp->irq, NULL, dw_dp_irq,
>+                                      IRQF_ONESHOT | IRQF_NO_AUTOEN, 
>dev_name(dev), dp);
>       if (ret) {
>-              dev_err_probe(dev, ret, "Failed to attach bridge\n");
>+              dev_err_probe(dev, ret, "failed to request irq\n");
>               return ERR_PTR(ret);
>       }
> 
>@@ -2090,28 +2102,19 @@ struct dw_dp *dw_dp_bind(struct device *dev, struct 
>drm_encoder *encoder,
>       if (ret)
>               return ERR_PTR(ret);
> 
>-      dp->irq = platform_get_irq(pdev, 0);
>-      if (dp->irq < 0) {
>-              ret = dp->irq;
>-              return ERR_PTR(ret);
>-      }
>+      bridge = &dp->bridge;
>+      bridge->of_node = dev->of_node;
>+      bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | 
>DRM_BRIDGE_OP_HPD;
>+      bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
>+      bridge->ycbcr_420_allowed = true;
> 
>-      ret = devm_request_threaded_irq(dev, dp->irq, NULL, dw_dp_irq,
>-                                      IRQF_ONESHOT, dev_name(dev), dp);
>-      if (ret) {
>-              dev_err_probe(dev, ret, "failed to request irq\n");
>+      ret = devm_drm_bridge_add(dev, bridge);
>+      if (ret)
>               return ERR_PTR(ret);
>-      }
> 
>       return dp;
> }
>-EXPORT_SYMBOL_GPL(dw_dp_bind);
>-
>-void dw_dp_unbind(struct dw_dp *dp)
>-{
>-      /* nothing to do */
>-}
>-EXPORT_SYMBOL_GPL(dw_dp_unbind);
>+EXPORT_SYMBOL_GPL(dw_dp_probe);
> 
> MODULE_AUTHOR("Andy Yan <[email protected]>");
> MODULE_DESCRIPTION("DW DP Core Library");
>diff --git a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c 
>b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
>index b23efb153c9e..38e8fe75718e 100644
>--- a/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
>+++ b/drivers/gpu/drm/rockchip/dw_dp-rockchip.c
>@@ -26,7 +26,7 @@
> struct rockchip_dw_dp {
>       struct dw_dp *base;
>       struct device *dev;
>-      struct rockchip_encoder encoder;
>+      struct rockchip_encoder *encoder;
> };
> 
> static int dw_dp_encoder_atomic_check(struct drm_encoder *encoder,
>@@ -73,37 +73,28 @@ static const struct drm_encoder_helper_funcs 
>dw_dp_encoder_helper_funcs = {
> 
> static int dw_dp_rockchip_bind(struct device *dev, struct device *master, 
> void *data)
> {
>-      struct platform_device *pdev = to_platform_device(dev);
>-      const struct dw_dp_plat_data *plat_data;
>+      struct rockchip_dw_dp *dp = dev_get_drvdata(dev);
>       struct drm_device *drm_dev = data;
>-      struct rockchip_dw_dp *dp;
>       struct drm_encoder *encoder;
>       struct drm_connector *connector;
>       int ret;
> 
>-      dp = drmm_kzalloc(drm_dev, sizeof(*dp), GFP_KERNEL);
>-      if (!dp)
>+      dp->encoder = drmm_kzalloc(drm_dev, sizeof(*dp->encoder), GFP_KERNEL);
>+      if (!dp->encoder)
>               return -ENOMEM;
> 
>-      dp->dev = dev;
>-      platform_set_drvdata(pdev, dp);
>-
>-      plat_data = of_device_get_match_data(dev);
>-      if (!plat_data)
>-              return -ENODEV;
>-
>-      encoder = &dp->encoder.encoder;
>+      encoder = &dp->encoder->encoder;
>       encoder->possible_crtcs = drm_of_find_possible_crtcs(drm_dev, 
> dev->of_node);
>-      rockchip_drm_encoder_set_crtc_endpoint_id(&dp->encoder, dev->of_node, 
>0, 0);
>+      rockchip_drm_encoder_set_crtc_endpoint_id(dp->encoder, dev->of_node, 0, 
>0);
> 
>       ret = drmm_encoder_init(drm_dev, encoder, NULL, DRM_MODE_ENCODER_TMDS, 
> NULL);
>       if (ret)
>               return ret;
>       drm_encoder_helper_add(encoder, &dw_dp_encoder_helper_funcs);
> 
>-      dp->base = dw_dp_bind(dev, encoder, plat_data);
>-      if (IS_ERR(dp->base))
>-              return PTR_ERR(dp->base);
>+      ret = dw_dp_bind(dp->base, encoder);
>+      if (ret)
>+              return dev_err_probe(dev, ret, "failed to bind DW-DP bridge\n");
> 
>       connector = drm_bridge_connector_init(drm_dev, encoder);
>       if (IS_ERR(connector)) {
>@@ -128,12 +119,30 @@ static const struct component_ops 
>dw_dp_rockchip_component_ops = {
>       .unbind = dw_dp_rockchip_unbind,
> };
> 
>-static int dw_dp_probe(struct platform_device *pdev)
>+static int dw_dp_rockchip_probe(struct platform_device *pdev)
> {
>+      const struct dw_dp_plat_data *plat_data;
>+      struct device *dev = &pdev->dev;
>+      struct rockchip_dw_dp *dp;
>+
>+      plat_data = of_device_get_match_data(dev);
>+      if (!plat_data)
>+              return -ENODEV;
>+
>+      dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
>+      if (!dp)
>+              return -ENOMEM;
>+      platform_set_drvdata(pdev, dp);
>+      dp->dev = dev;
>+
>+      dp->base = dw_dp_probe(pdev, plat_data);
>+      if (IS_ERR(dp->base))
>+              return PTR_ERR(dp->base);
>+
>       return component_add(&pdev->dev, &dw_dp_rockchip_component_ops);
> }
> 
>-static void dw_dp_remove(struct platform_device *pdev)
>+static void dw_dp_rockchip_remove(struct platform_device *pdev)
> {
>       component_del(&pdev->dev, &dw_dp_rockchip_component_ops);
> }
>@@ -161,8 +170,8 @@ static const struct of_device_id dw_dp_of_match[] = {
> MODULE_DEVICE_TABLE(of, dw_dp_of_match);
> 
> struct platform_driver dw_dp_driver = {
>-      .probe  = dw_dp_probe,
>-      .remove = dw_dp_remove,
>+      .probe  = dw_dp_rockchip_probe,
>+      .remove = dw_dp_rockchip_remove,
>       .driver = {
>               .name = "dw-dp",
>               .of_match_table = dw_dp_of_match,
>diff --git a/include/drm/bridge/dw_dp.h b/include/drm/bridge/dw_dp.h
>index 22105c3e8e4d..a82412a9e769 100644
>--- a/include/drm/bridge/dw_dp.h
>+++ b/include/drm/bridge/dw_dp.h
>@@ -22,7 +22,8 @@ struct dw_dp_plat_data {
>       u8 pixel_mode;
> };
> 
>-struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
>-                       const struct dw_dp_plat_data *plat_data);
>+int dw_dp_bind(struct dw_dp *dp, struct drm_encoder *encoder);
> void dw_dp_unbind(struct dw_dp *dp);
>+
>+struct dw_dp *dw_dp_probe(struct platform_device *pdev, const struct 
>dw_dp_plat_data *plat_data);
> #endif /* __DW_DP__ */
>
>-- 
>2.53.0
>

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