[PATCH v5 0/3] Fix IS_ERR() vs NULL check for drm

[PATCH v5 0/3] Fix IS_ERR() vs NULL check for drm

[Gaosheng Cui]

v5:
- Update the third patch, change IS_ERR to IS_ERR_OR_NULL.
  Thanks!

v4:
- 1. Update the second patch's commit messages.
  2. Update the first patch, use dev_err_probe() instead of dev_err().

  Thanks!

v3:
- Update the second patch:
  1. change IS_ERR to IS_ERR_OR_NULL
  2. add Dmitry's R-b in this revision:
  link: https://patchwork.freedesktop.org/patch/511035/?series=110745&rev=1

  Thanks!

v2:
- I'm sorry I missed some emails, these patches were submitted last year,
  now let me resend it with the following changes:
  1. remove the patch: "drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in msm_icc_get()"
  2. remove the patch: "drm/vc4: kms: Fix IS_ERR() vs NULL check for vc4_kms"
  3. add "Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>" to the second patch.

  Thanks!

v1:
- This series contains a few fixup patches, to fix IS_ERR() vs NULL check
  for drm, and avoid a potential null-ptr-defer issue, too. Thanks!

Gaosheng Cui (3):
  drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()
  drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()
  drm/komeda: Fix IS_ERR_OR_NULL() vs NULL check in
    komeda_component_get_avail_scaler()

 drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c | 2 +-
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c                      | 2 +-
 drivers/gpu/drm/panel/panel-novatek-nt35950.c              | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

-- 
2.25.1

[PATCH v5 0/3] Fix IS_ERR() vs NULL check for drm

[Gaosheng Cui]

v5:
- Update the third patch, change IS_ERR to IS_ERR_OR_NULL.
  Thanks!

v4:
- 1. Update the second patch's commit messages.
  2. Update the first patch, use dev_err_probe() instead of dev_err().

  Thanks!

v3:
- Update the second patch:
  1. change IS_ERR to IS_ERR_OR_NULL
  2. add Dmitry's R-b in this revision:
  link: https://patchwork.freedesktop.org/patch/511035/?series=110745&rev=1

  Thanks!

v2:
- I'm sorry I missed some emails, these patches were submitted last year,
  now let me resend it with the following changes:
  1. remove the patch: "drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in msm_icc_get()"
  2. remove the patch: "drm/vc4: kms: Fix IS_ERR() vs NULL check for vc4_kms"
  3. add "Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>" to the second patch.

  Thanks!

v1:
- This series contains a few fixup patches, to fix IS_ERR() vs NULL check
  for drm, and avoid a potential null-ptr-defer issue, too. Thanks!

Gaosheng Cui (3):
  drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()
  drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()
  drm/komeda: Fix IS_ERR_OR_NULL() vs NULL check in
    komeda_component_get_avail_scaler()

 drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c | 2 +-
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c                      | 2 +-
 drivers/gpu/drm/panel/panel-novatek-nt35950.c              | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

-- 
2.25.1

[PATCH v5 1/3] drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()

[Gaosheng Cui]

The mipi_dsi_device_register_full() returns an ERR_PTR() on failure,
we should use IS_ERR() to check the return value.

By the way, use dev_err_probe instead of dev_err to print the error code.

Fixes: 623a3531e9cf ("drm/panel: Add driver for Novatek NT35950 DSI DriverIC panels")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
---
 drivers/gpu/drm/panel/panel-novatek-nt35950.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
index 8b108ac80b55..2731ce02ce53 100644
--- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
+++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
@@ -571,8 +571,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
 		}
 
 		nt->dsi[1] = mipi_dsi_device_register_full(dsi_r_host, info);
-		if (!nt->dsi[1]) {
-			dev_err(dev, "Cannot get secondary DSI node\n");
+		if (IS_ERR(nt->dsi[1])) {
+			dev_err_probe(dev, PTR_ERR(nt->dsi[1]), "Cannot get secondary DSI node\n");
 			return -ENODEV;
 		}
 		num_dsis++;
-- 
2.25.1

[PATCH v5 1/3] drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()

[Gaosheng Cui]

The mipi_dsi_device_register_full() returns an ERR_PTR() on failure,
we should use IS_ERR() to check the return value.

By the way, use dev_err_probe instead of dev_err to print the error code.

Fixes: 623a3531e9cf ("drm/panel: Add driver for Novatek NT35950 DSI DriverIC panels")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
---
 drivers/gpu/drm/panel/panel-novatek-nt35950.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
index 8b108ac80b55..2731ce02ce53 100644
--- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
+++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
@@ -571,8 +571,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
 		}
 
 		nt->dsi[1] = mipi_dsi_device_register_full(dsi_r_host, info);
-		if (!nt->dsi[1]) {
-			dev_err(dev, "Cannot get secondary DSI node\n");
+		if (IS_ERR(nt->dsi[1])) {
+			dev_err_probe(dev, PTR_ERR(nt->dsi[1]), "Cannot get secondary DSI node\n");
 			return -ENODEV;
 		}
 		num_dsis++;
-- 
2.25.1

[PATCH v5 2/3] drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()

[Gaosheng Cui]

The msm_gem_get_vaddr() returns an ERR_PTR() on failure, and a null
is catastrophic here, so we should use IS_ERR_OR_NULL() to check
the return value.

Fixes: 6a8bd08d0465 ("drm/msm: add sudo flag to submit ioctl")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index a99310b68793..bbb1bf33f98e 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -89,7 +89,7 @@ static void a5xx_submit_in_rb(struct msm_gpu *gpu, struct msm_gem_submit *submit
 			 * since we've already mapped it once in
 			 * submit_reloc()
 			 */
-			if (WARN_ON(!ptr))
+			if (WARN_ON(IS_ERR_OR_NULL(ptr)))
 				return;
 
 			for (i = 0; i < dwords; i++) {
-- 
2.25.1

[PATCH v5 2/3] drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()

[Gaosheng Cui]

The msm_gem_get_vaddr() returns an ERR_PTR() on failure, and a null
is catastrophic here, so we should use IS_ERR_OR_NULL() to check
the return value.

Fixes: 6a8bd08d0465 ("drm/msm: add sudo flag to submit ioctl")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index a99310b68793..bbb1bf33f98e 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -89,7 +89,7 @@ static void a5xx_submit_in_rb(struct msm_gpu *gpu, struct msm_gem_submit *submit
 			 * since we've already mapped it once in
 			 * submit_reloc()
 			 */
-			if (WARN_ON(!ptr))
+			if (WARN_ON(IS_ERR_OR_NULL(ptr)))
 				return;
 
 			for (i = 0; i < dwords; i++) {
-- 
2.25.1

[PATCH v5 3/3] drm/komeda: Fix IS_ERR_OR_NULL() vs NULL check in komeda_component_get_avail_scaler()

[Gaosheng Cui]

The komeda_pipeline_get_state() returns an ERR_PTR() on failure,
and a null is catastrophic here we should use IS_ERR_OR_NULL()
to check the return value.

Fixes: 502932a03fce ("drm/komeda: Add the initial scaler support for CORE")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
index 3276a3e82c62..f7281dd99727 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
@@ -259,7 +259,7 @@ komeda_component_get_avail_scaler(struct komeda_component *c,
 	u32 avail_scalers;
 
 	pipe_st = komeda_pipeline_get_state(c->pipeline, state);
-	if (!pipe_st)
+	if (IS_ERR_OR_NULL(pipe_st))
 		return NULL;
 
 	avail_scalers = (pipe_st->active_comps & KOMEDA_PIPELINE_SCALERS) ^
-- 
2.25.1

[PATCH v5 3/3] drm/komeda: Fix IS_ERR_OR_NULL() vs NULL check in komeda_component_get_avail_scaler()

[Gaosheng Cui]

The komeda_pipeline_get_state() returns an ERR_PTR() on failure,
and a null is catastrophic here we should use IS_ERR_OR_NULL()
to check the return value.

Fixes: 502932a03fce ("drm/komeda: Add the initial scaler support for CORE")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
index 3276a3e82c62..f7281dd99727 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
@@ -259,7 +259,7 @@ komeda_component_get_avail_scaler(struct komeda_component *c,
 	u32 avail_scalers;
 
 	pipe_st = komeda_pipeline_get_state(c->pipeline, state);
-	if (!pipe_st)
+	if (IS_ERR_OR_NULL(pipe_st))
 		return NULL;
 
 	avail_scalers = (pipe_st->active_comps & KOMEDA_PIPELINE_SCALERS) ^
-- 
2.25.1

Re: [PATCH v5 1/3] drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()

[Sam Ravnborg]

Hi Gaosheng,
On Mon, Jul 24, 2023 at 10:00:34PM +0800, Gaosheng Cui wrote:
> The mipi_dsi_device_register_full() returns an ERR_PTR() on failure,
> we should use IS_ERR() to check the return value.
> 
> By the way, use dev_err_probe instead of dev_err to print the error code.
> 
> Fixes: 623a3531e9cf ("drm/panel: Add driver for Novatek NT35950 DSI DriverIC panels")
> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
> ---
>  drivers/gpu/drm/panel/panel-novatek-nt35950.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> index 8b108ac80b55..2731ce02ce53 100644
> --- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> +++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> @@ -571,8 +571,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
>  		}
>  
>  		nt->dsi[1] = mipi_dsi_device_register_full(dsi_r_host, info);
> -		if (!nt->dsi[1]) {
> -			dev_err(dev, "Cannot get secondary DSI node\n");
> +		if (IS_ERR(nt->dsi[1])) {
> +			dev_err_probe(dev, PTR_ERR(nt->dsi[1]), "Cannot get secondary DSI node\n");
>  			return -ENODEV;
This code should return the error code we get from
mipi_dsi_device_register_full().

To do so use:
	
	return dev_err_probe(...);

Please fix and sorry for not noticing before.

	Sam

Re: [PATCH v5 1/3] drm/panel: Fix IS_ERR() vs NULL check in nt35950_probe()

[Sam Ravnborg]

Hi Gaosheng,
On Mon, Jul 24, 2023 at 10:00:34PM +0800, Gaosheng Cui wrote:
> The mipi_dsi_device_register_full() returns an ERR_PTR() on failure,
> we should use IS_ERR() to check the return value.
> 
> By the way, use dev_err_probe instead of dev_err to print the error code.
> 
> Fixes: 623a3531e9cf ("drm/panel: Add driver for Novatek NT35950 DSI DriverIC panels")
> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
> ---
>  drivers/gpu/drm/panel/panel-novatek-nt35950.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> index 8b108ac80b55..2731ce02ce53 100644
> --- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> +++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
> @@ -571,8 +571,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
>  		}
>  
>  		nt->dsi[1] = mipi_dsi_device_register_full(dsi_r_host, info);
> -		if (!nt->dsi[1]) {
> -			dev_err(dev, "Cannot get secondary DSI node\n");
> +		if (IS_ERR(nt->dsi[1])) {
> +			dev_err_probe(dev, PTR_ERR(nt->dsi[1]), "Cannot get secondary DSI node\n");
>  			return -ENODEV;
This code should return the error code we get from
mipi_dsi_device_register_full().

To do so use:
	
	return dev_err_probe(...);

Please fix and sorry for not noticing before.

	Sam