[PATCH 0/3] drm/msm: Better unknown GPU handling

[PATCH 0/3] drm/msm: Better unknown GPU handling

[Rob Clark]

Detect earlier if the GPU is supported, and skip binding the GPU
sub-component if not.  This way the rest of the driver can still
probe and get working display if the only thing unsupported is
the GPU.

Rob Clark (3):
  drm/msm: Rename add_components_mdp()
  drm/msm/adreno: Pass device_node to find_chipid()
  drm/msm/adreno: Check for recognized GPU before bind

 drivers/gpu/drm/msm/adreno/adreno_device.c | 39 ++++++++++++++++------
 drivers/gpu/drm/msm/msm_drv.c              |  6 ++--
 drivers/gpu/drm/msm/msm_gpu.h              |  1 +
 3 files changed, 33 insertions(+), 13 deletions(-)

-- 
2.49.0

[PATCH 1/3] drm/msm: Rename add_components_mdp()

[Rob Clark]

To better match add_gpu_components().

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 710046906229..87ee9839ca4a 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -852,7 +852,7 @@ static const struct drm_driver msm_driver = {
  * is no external component that we need to add since LVDS is within MDP4
  * itself.
  */
-static int add_components_mdp(struct device *master_dev,
+static int add_mdp_components(struct device *master_dev,
 			      struct component_match **matchptr)
 {
 	struct device_node *np = master_dev->of_node;
@@ -997,7 +997,7 @@ int msm_drv_probe(struct device *master_dev,
 
 	/* Add mdp components if we have KMS. */
 	if (kms_init) {
-		ret = add_components_mdp(master_dev, &match);
+		ret = add_mdp_components(master_dev, &match);
 		if (ret)
 			return ret;
 	}
-- 
2.49.0

[PATCH 2/3] drm/msm/adreno: Pass device_node to find_chipid()

[Rob Clark]

We are going to want to re-use this before the component is bound, when
we don't yet have the device pointer (but we do have the of node).

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 6b0390c38bff..504174dbe6d6 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -133,9 +133,8 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 	return NULL;
 }
 
-static int find_chipid(struct device *dev, uint32_t *chipid)
+static int find_chipid(struct device_node *node, uint32_t *chipid)
 {
-	struct device_node *node = dev->of_node;
 	const char *compat;
 	int ret;
 
@@ -169,11 +168,12 @@ static int find_chipid(struct device *dev, uint32_t *chipid)
 	/* and if that fails, fall back to legacy "qcom,chipid" property: */
 	ret = of_property_read_u32(node, "qcom,chipid", chipid);
 	if (ret) {
-		DRM_DEV_ERROR(dev, "could not parse qcom,chipid: %d\n", ret);
+		DRM_ERROR("%s: could not parse qcom,chipid: %d\n",
+			  node->full_name, ret);
 		return ret;
 	}
 
-	dev_warn(dev, "Using legacy qcom,chipid binding!\n");
+	pr_warn("%s: Using legacy qcom,chipid binding!\n", node->full_name);
 
 	return 0;
 }
@@ -187,7 +187,7 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 	struct msm_gpu *gpu;
 	int ret;
 
-	ret = find_chipid(dev, &config.chip_id);
+	ret = find_chipid(dev->of_node, &config.chip_id);
 	if (ret)
 		return ret;
 
-- 
2.49.0

[PATCH 3/3] drm/msm/adreno: Check for recognized GPU before bind

[Rob Clark]

If we have a newer dtb than kernel, we could end up in a situation where
the GPU device is present in the dtb, but not in the drivers device
table.  We don't want this to prevent the display from probing.  So
check that we recognize the GPU before adding the GPU component.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 29 ++++++++++++++++++----
 drivers/gpu/drm/msm/msm_drv.c              |  2 +-
 drivers/gpu/drm/msm/msm_gpu.h              |  1 +
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 504174dbe6d6..002aaf365322 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -178,6 +178,26 @@ static int find_chipid(struct device_node *node, uint32_t *chipid)
 	return 0;
 }
 
+bool adreno_has_gpu(struct device_node *node)
+{
+	const struct adreno_info *info;
+	uint32_t chip_id;
+	int ret;
+
+	ret = find_chipid(node, &chip_id);
+	if (ret)
+		return false;
+
+	info = adreno_info(chip_id);
+	if (!info) {
+		pr_warn("%s: Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",
+			node->full_name, ADRENO_CHIPID_ARGS(chip_id));
+		return false;
+	}
+
+	return true;
+}
+
 static int adreno_bind(struct device *dev, struct device *master, void *data)
 {
 	static struct adreno_platform_config config = {};
@@ -188,18 +208,17 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 	int ret;
 
 	ret = find_chipid(dev->of_node, &config.chip_id);
-	if (ret)
+	/* We shouldn't have gotten this far if we can't parse the chip_id */
+	if (WARN_ON(ret))
 		return ret;
 
 	dev->platform_data = &config;
 	priv->gpu_pdev = to_platform_device(dev);
 
 	info = adreno_info(config.chip_id);
-	if (!info) {
-		dev_warn(drm->dev, "Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",
-			ADRENO_CHIPID_ARGS(config.chip_id));
+	/* We shouldn't have gotten this far if we don't recognize the GPU: */
+	if (!WARN_ON(info))
 		return -ENXIO;
-	}
 
 	config.info = info;
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 87ee9839ca4a..40eb04bab35e 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -956,7 +956,7 @@ static int add_gpu_components(struct device *dev,
 	if (!np)
 		return 0;
 
-	if (of_device_is_available(np))
+	if (of_device_is_available(np) && adreno_has_gpu(np))
 		drm_of_component_match_add(dev, matchptr, component_compare_of, np);
 
 	of_node_put(np);
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 5508885d865f..56bd1a646b83 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -729,6 +729,7 @@ msm_gpu_create_private_vm(struct msm_gpu *gpu, struct task_struct *task,
 void msm_gpu_cleanup(struct msm_gpu *gpu);
 
 struct msm_gpu *adreno_load_gpu(struct drm_device *dev);
+bool adreno_has_gpu(struct device_node *node);
 void __init adreno_register(void);
 void __exit adreno_unregister(void);
 
-- 
2.49.0

Re: [PATCH 3/3] drm/msm/adreno: Check for recognized GPU before bind

[Dmitry Baryshkov]

On 09/06/2025 20:04, Rob Clark wrote:
> If we have a newer dtb than kernel, we could end up in a situation where
> the GPU device is present in the dtb, but not in the drivers device
> table.  We don't want this to prevent the display from probing.  So
> check that we recognize the GPU before adding the GPU component.
> 
> Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
> ---
>   drivers/gpu/drm/msm/adreno/adreno_device.c | 29 ++++++++++++++++++----
>   drivers/gpu/drm/msm/msm_drv.c              |  2 +-
>   drivers/gpu/drm/msm/msm_gpu.h              |  1 +
>   3 files changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index 504174dbe6d6..002aaf365322 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -178,6 +178,26 @@ static int find_chipid(struct device_node *node, uint32_t *chipid)
>   	return 0;
>   }
>   
> +bool adreno_has_gpu(struct device_node *node)
> +{
> +	const struct adreno_info *info;
> +	uint32_t chip_id;
> +	int ret;
> +
> +	ret = find_chipid(node, &chip_id);
> +	if (ret)
> +		return false;
> +
> +	info = adreno_info(chip_id);
> +	if (!info) {
> +		pr_warn("%s: Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",

Please use %pOFf instead of %s (and node instead of node->full_name).

Other than that, LGTM.

> +			node->full_name, ADRENO_CHIPID_ARGS(chip_id));
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
>   static int adreno_bind(struct device *dev, struct device *master, void *data)
>   {
>   	static struct adreno_platform_config config = {};
> @@ -188,18 +208,17 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
>   	int ret;
>   
>   	ret = find_chipid(dev->of_node, &config.chip_id);
> -	if (ret)
> +	/* We shouldn't have gotten this far if we can't parse the chip_id */
> +	if (WARN_ON(ret))
>   		return ret;
>   
>   	dev->platform_data = &config;
>   	priv->gpu_pdev = to_platform_device(dev);
>   
>   	info = adreno_info(config.chip_id);
> -	if (!info) {
> -		dev_warn(drm->dev, "Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",
> -			ADRENO_CHIPID_ARGS(config.chip_id));
> +	/* We shouldn't have gotten this far if we don't recognize the GPU: */
> +	if (!WARN_ON(info))
>   		return -ENXIO;
> -	}
>   
>   	config.info = info;
>   
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 87ee9839ca4a..40eb04bab35e 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -956,7 +956,7 @@ static int add_gpu_components(struct device *dev,
>   	if (!np)
>   		return 0;
>   
> -	if (of_device_is_available(np))
> +	if (of_device_is_available(np) && adreno_has_gpu(np))
>   		drm_of_component_match_add(dev, matchptr, component_compare_of, np);
>   
>   	of_node_put(np);
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index 5508885d865f..56bd1a646b83 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -729,6 +729,7 @@ msm_gpu_create_private_vm(struct msm_gpu *gpu, struct task_struct *task,
>   void msm_gpu_cleanup(struct msm_gpu *gpu);
>   
>   struct msm_gpu *adreno_load_gpu(struct drm_device *dev);
> +bool adreno_has_gpu(struct device_node *node);
>   void __init adreno_register(void);
>   void __exit adreno_unregister(void);
>   


-- 
With best wishes
Dmitry