[PATCH v2] drm/imx/ipuv3: Fix dumb-buffer allocation for non-RGB formats

[PATCH v2] drm/imx/ipuv3: Fix dumb-buffer allocation for non-RGB formats

[Thomas Zimmermann]

Align pitch to multiples of 8 pixels for bpp values that do not map
to RGB formats. The call to drm_driver_color_mode_format() fails with
DRM_INVALID_FORMAT in these cases. Fall back to manually computing
the pitch alignment from which drm_mode_size_dumb() can compute the
correct pitch.

Fixes userspace that allocates dumb buffers for YUV formats, where
bpp equals 12. A common example is the IGT kms_getfb test.

v2:
- ignore width in calculation

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: b1d0e470f881 ("drm/imx/ipuv3: Compute dumb-buffer sizes with drm_mode_size_dumb()")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
---
This patch is based on Dmitry's fix for msm. [1] Please test.

There could later be a helper to contain these aligmentment calculations
in a single place.

[1] https://lore.kernel.org/dri-devel/20251103-drm-msm-fix-nv12-v2-1-75103b64576e@oss.qualcomm.com/
---
 drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
index 465b5a6ad5bb..eddb471119c6 100644
--- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
@@ -144,7 +144,6 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
 			       struct drm_mode_create_dumb *args)
 {
 	u32 fourcc;
-	const struct drm_format_info *info;
 	u64 pitch_align;
 	int ret;
 
@@ -156,12 +155,15 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
 	 * the allocated buffer.
 	 */
 	fourcc = drm_driver_color_mode_format(drm, args->bpp);
-	if (fourcc == DRM_FORMAT_INVALID)
-		return -EINVAL;
-	info = drm_format_info(fourcc);
-	if (!info)
-		return -EINVAL;
-	pitch_align = drm_format_info_min_pitch(info, 0, SZ_8);
+	if (fourcc != DRM_FORMAT_INVALID) {
+		const struct drm_format_info *info = drm_format_info(fourcc);
+
+		if (!info)
+			return -EINVAL;
+		pitch_align = drm_format_info_min_pitch(info, 0, 8);
+	} else {
+		pitch_align = DIV_ROUND_UP(args->bpp, SZ_8) * 8;
+	}
 	if (!pitch_align || pitch_align > U32_MAX)
 		return -EINVAL;
 	ret = drm_mode_size_dumb(drm, args, pitch_align, 0);
-- 
2.51.1

Re: [PATCH v2] drm/imx/ipuv3: Fix dumb-buffer allocation for non-RGB formats

[Thomas Zimmermann]

Ping! Could this patch please get a timely review from imx maintainers?  
Not fixing this bug could break user space.

Am 04.11.25 um 16:38 schrieb Thomas Zimmermann:
> Align pitch to multiples of 8 pixels for bpp values that do not map
> to RGB formats. The call to drm_driver_color_mode_format() fails with
> DRM_INVALID_FORMAT in these cases. Fall back to manually computing
> the pitch alignment from which drm_mode_size_dumb() can compute the
> correct pitch.
>
> Fixes userspace that allocates dumb buffers for YUV formats, where
> bpp equals 12. A common example is the IGT kms_getfb test.
>
> v2:
> - ignore width in calculation
>
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: b1d0e470f881 ("drm/imx/ipuv3: Compute dumb-buffer sizes with drm_mode_size_dumb()")
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: imx@lists.linux.dev
> Cc: linux-arm-kernel@lists.infradead.org
> ---
> This patch is based on Dmitry's fix for msm. [1] Please test.
>
> There could later be a helper to contain these aligmentment calculations
> in a single place.
>
> [1] https://lore.kernel.org/dri-devel/20251103-drm-msm-fix-nv12-v2-1-75103b64576e@oss.qualcomm.com/
> ---
>   drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 16 +++++++++-------
>   1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> index 465b5a6ad5bb..eddb471119c6 100644
> --- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> +++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> @@ -144,7 +144,6 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>   			       struct drm_mode_create_dumb *args)
>   {
>   	u32 fourcc;
> -	const struct drm_format_info *info;
>   	u64 pitch_align;
>   	int ret;
>   
> @@ -156,12 +155,15 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>   	 * the allocated buffer.
>   	 */
>   	fourcc = drm_driver_color_mode_format(drm, args->bpp);
> -	if (fourcc == DRM_FORMAT_INVALID)
> -		return -EINVAL;
> -	info = drm_format_info(fourcc);
> -	if (!info)
> -		return -EINVAL;
> -	pitch_align = drm_format_info_min_pitch(info, 0, SZ_8);
> +	if (fourcc != DRM_FORMAT_INVALID) {
> +		const struct drm_format_info *info = drm_format_info(fourcc);
> +
> +		if (!info)
> +			return -EINVAL;
> +		pitch_align = drm_format_info_min_pitch(info, 0, 8);
> +	} else {
> +		pitch_align = DIV_ROUND_UP(args->bpp, SZ_8) * 8;
> +	}
>   	if (!pitch_align || pitch_align > U32_MAX)
>   		return -EINVAL;
>   	ret = drm_mode_size_dumb(drm, args, pitch_align, 0);

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

Re: [PATCH v2] drm/imx/ipuv3: Fix dumb-buffer allocation for non-RGB formats

[Philipp Zabel]

On Di, 2025-11-04 at 16:38 +0100, Thomas Zimmermann wrote:
> Align pitch to multiples of 8 pixels for bpp values that do not map
> to RGB formats. The call to drm_driver_color_mode_format() fails with
> DRM_INVALID_FORMAT in these cases. Fall back to manually computing
> the pitch alignment from which drm_mode_size_dumb() can compute the
> correct pitch.
> 
> Fixes userspace that allocates dumb buffers for YUV formats, where
> bpp equals 12. A common example is the IGT kms_getfb test.
>
> v2:
> - ignore width in calculation
> 
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: b1d0e470f881 ("drm/imx/ipuv3: Compute dumb-buffer sizes with drm_mode_size_dumb()")
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: imx@lists.linux.dev
> Cc: linux-arm-kernel@lists.infradead.org
> ---
> This patch is based on Dmitry's fix for msm. [1] Please test.

Thank you,

[IGT] kms_getfb: finished subtest getfb2-accept-nv12, CRASH -> SUCCESS

Tested-by: Philipp Zabel <p.zabel@pengutronix.de>

> There could later be a helper to contain these aligmentment calculations
> in a single place.
> 
> [1] https://lore.kernel.org/dri-devel/20251103-drm-msm-fix-nv12-v2-1-75103b64576e@oss.qualcomm.com/
> ---
>  drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> index 465b5a6ad5bb..eddb471119c6 100644
> --- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> +++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
> @@ -144,7 +144,6 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>  			       struct drm_mode_create_dumb *args)
>  {
>  	u32 fourcc;
> -	const struct drm_format_info *info;
>  	u64 pitch_align;
>  	int ret;
>  
> @@ -156,12 +155,15 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>  	 * the allocated buffer.
>  	 */
>  	fourcc = drm_driver_color_mode_format(drm, args->bpp);
> -	if (fourcc == DRM_FORMAT_INVALID)
> -		return -EINVAL;
> -	info = drm_format_info(fourcc);
> -	if (!info)
> -		return -EINVAL;
> -	pitch_align = drm_format_info_min_pitch(info, 0, SZ_8);
> +	if (fourcc != DRM_FORMAT_INVALID) {
> +		const struct drm_format_info *info = drm_format_info(fourcc);
> +
> +		if (!info)
> +			return -EINVAL;
> +		pitch_align = drm_format_info_min_pitch(info, 0, 8);
> +	} else {
> +		pitch_align = DIV_ROUND_UP(args->bpp, SZ_8) * 8;
> +	}
>  	if (!pitch_align || pitch_align > U32_MAX)
>  		return -EINVAL;
>  	ret = drm_mode_size_dumb(drm, args, pitch_align, 0);

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

Re: [PATCH v2] drm/imx/ipuv3: Fix dumb-buffer allocation for non-RGB formats

[Thomas Zimmermann]

Hi

Am 12.11.25 um 13:53 schrieb Philipp Zabel:
> On Di, 2025-11-04 at 16:38 +0100, Thomas Zimmermann wrote:
>> Align pitch to multiples of 8 pixels for bpp values that do not map
>> to RGB formats. The call to drm_driver_color_mode_format() fails with
>> DRM_INVALID_FORMAT in these cases. Fall back to manually computing
>> the pitch alignment from which drm_mode_size_dumb() can compute the
>> correct pitch.
>>
>> Fixes userspace that allocates dumb buffers for YUV formats, where
>> bpp equals 12. A common example is the IGT kms_getfb test.
>>
>> v2:
>> - ignore width in calculation
>>
>> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> Fixes: b1d0e470f881 ("drm/imx/ipuv3: Compute dumb-buffer sizes with drm_mode_size_dumb()")
>> Cc: Thomas Zimmermann <tzimmermann@suse.de>
>> Cc: Philipp Zabel <p.zabel@pengutronix.de>
>> Cc: Shawn Guo <shawnguo@kernel.org>
>> Cc: Sascha Hauer <s.hauer@pengutronix.de>
>> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
>> Cc: Fabio Estevam <festevam@gmail.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: imx@lists.linux.dev
>> Cc: linux-arm-kernel@lists.infradead.org
>> ---
>> This patch is based on Dmitry's fix for msm. [1] Please test.
> Thank you,
>
> [IGT] kms_getfb: finished subtest getfb2-accept-nv12, CRASH -> SUCCESS
>
> Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
>
>> There could later be a helper to contain these aligmentment calculations
>> in a single place.
>>
>> [1] https://lore.kernel.org/dri-devel/20251103-drm-msm-fix-nv12-v2-1-75103b64576e@oss.qualcomm.com/
>> ---
>>   drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 16 +++++++++-------
>>   1 file changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
>> index 465b5a6ad5bb..eddb471119c6 100644
>> --- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
>> +++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
>> @@ -144,7 +144,6 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>>   			       struct drm_mode_create_dumb *args)
>>   {
>>   	u32 fourcc;
>> -	const struct drm_format_info *info;
>>   	u64 pitch_align;
>>   	int ret;
>>   
>> @@ -156,12 +155,15 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
>>   	 * the allocated buffer.
>>   	 */
>>   	fourcc = drm_driver_color_mode_format(drm, args->bpp);
>> -	if (fourcc == DRM_FORMAT_INVALID)
>> -		return -EINVAL;
>> -	info = drm_format_info(fourcc);
>> -	if (!info)
>> -		return -EINVAL;
>> -	pitch_align = drm_format_info_min_pitch(info, 0, SZ_8);
>> +	if (fourcc != DRM_FORMAT_INVALID) {
>> +		const struct drm_format_info *info = drm_format_info(fourcc);
>> +
>> +		if (!info)
>> +			return -EINVAL;
>> +		pitch_align = drm_format_info_min_pitch(info, 0, 8);
>> +	} else {
>> +		pitch_align = DIV_ROUND_UP(args->bpp, SZ_8) * 8;
>> +	}
>>   	if (!pitch_align || pitch_align > U32_MAX)
>>   		return -EINVAL;
>>   	ret = drm_mode_size_dumb(drm, args, pitch_align, 0);
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

Thanks a lot. I'll land this fix ASAP.

Best regards
Thomas

>
> regards
> Philipp

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)