1. Patchew
  2. linux
  3. [PATCH v3 0/4] media: rzg2l-cru: Fix DMA stride alignment
  4. View patch

[PATCH v3 4/4] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement

Tommaso Merciai posted 4 patches 1 month, 1 week ago
There is a newer version of this series
[PATCH v3 4/4] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
Posted by Tommaso Merciai 1 month, 1 week ago 
The RZ/G3E CRU programs the line stride via the AMnIS register, whose
IS field encodes the value in units of 128 bytes. If bytesperline is
not a multiple of 128, the division truncates and the hardware uses a
wrong stride, causing horizontal banding.

Commit ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
replaced the open-coded aligned calculation with v4l2_fill_pixfmt(),
which sets no alignment, reintroducing the issue.

Switch to v4l2_fill_pixfmt_aligned() with RZG2L_CRU_STRIDE_ALIGN when
info->has_stride is set. RZ/G2L has no AMnIS register and keeps using
v4l2_fill_pixfmt() unchanged.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: stable@vger.kernel.org
Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v2->v3:
 - No changes.

v1->v2:
 - Collected tag
 - Add missing Cc stable
 - Fix s/commit/Commit/ into commit body

 drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
index 69346a585f9f..478264f26466 100644
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
@@ -860,7 +860,8 @@ static void rzg2l_cru_format_align(struct rzg2l_cru_dev *cru,
 	v4l_bound_align_image(&pix->width, 320, info->max_width, 1,
 			      &pix->height, 240, info->max_height, 0, 0);
 
-	v4l2_fill_pixfmt(pix, pix->pixelformat, pix->width, pix->height);
+	v4l2_fill_pixfmt_aligned(pix, pix->pixelformat, pix->width, pix->height,
+				 info->has_stride ? RZG2L_CRU_STRIDE_ALIGN : 1);
 
 	dev_dbg(cru->dev, "Format %ux%u bpl: %u size: %u\n",
 		pix->width, pix->height, pix->bytesperline, pix->sizeimage);
-- 
2.54.0
Re: [PATCH v3 4/4] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
Posted by Jacopo Mondi 1 month, 1 week ago 
Hi Tommaso

On Wed, Jul 08, 2026 at 06:14:05PM +0200, Tommaso Merciai wrote:
> The RZ/G3E CRU programs the line stride via the AMnIS register, whose
> IS field encodes the value in units of 128 bytes. If bytesperline is

Unrelated, it seems for RGB888 the alignemtn requirement is 384 bytes,
something that doesn't seem handled at the moment ?

> not a multiple of 128, the division truncates and the hardware uses a
> wrong stride, causing horizontal banding.
>
> Commit ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
> replaced the open-coded aligned calculation with v4l2_fill_pixfmt(),
> which sets no alignment, reintroducing the issue.
>
> Switch to v4l2_fill_pixfmt_aligned() with RZG2L_CRU_STRIDE_ALIGN when
> info->has_stride is set. RZ/G2L has no AMnIS register and keeps using
> v4l2_fill_pixfmt() unchanged.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Cc: stable@vger.kernel.org
> Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> ---
> v2->v3:
>  - No changes.
>
> v1->v2:
>  - Collected tag
>  - Add missing Cc stable
>  - Fix s/commit/Commit/ into commit body
>
>  drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> index 69346a585f9f..478264f26466 100644
> --- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> @@ -860,7 +860,8 @@ static void rzg2l_cru_format_align(struct rzg2l_cru_dev *cru,
>  	v4l_bound_align_image(&pix->width, 320, info->max_width, 1,
>  			      &pix->height, 240, info->max_height, 0, 0);

This doesn't apply on media-committers/next which has

	v4l_bound_align_image(&pix->width, 320, info->max_width, 1,
			      &pix->height, 240, info->max_height, 2, 0);

in this line.

What have I missed ?

>
> -	v4l2_fill_pixfmt(pix, pix->pixelformat, pix->width, pix->height);
> +	v4l2_fill_pixfmt_aligned(pix, pix->pixelformat, pix->width, pix->height,
> +				 info->has_stride ? RZG2L_CRU_STRIDE_ALIGN : 1);

Rebasing apart, this seems correct

Reviewed-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>

Thanks
  j

>
>  	dev_dbg(cru->dev, "Format %ux%u bpl: %u size: %u\n",
>  		pix->width, pix->height, pix->bytesperline, pix->sizeimage);
> --
> 2.54.0
>
>
Re: [PATCH v3 4/4] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
Posted by Tommaso Merciai 1 month, 1 week ago 
Hi Jacopo,
Thanks for your review.

On Thu, Jul 09, 2026 at 11:19:17AM +0200, Jacopo Mondi wrote:
> Hi Tommaso
> 
> On Wed, Jul 08, 2026 at 06:14:05PM +0200, Tommaso Merciai wrote:
> > The RZ/G3E CRU programs the line stride via the AMnIS register, whose
> > IS field encodes the value in units of 128 bytes. If bytesperline is
> 
> Unrelated, it seems for RGB888 the alignemtn requirement is 384 bytes,
> something that doesn't seem handled at the moment ?

Yes, I had a similar discussion with Laurent at [1]

Currently neither RGB888 nor semi-planar YUV 4:2:0 are supported.
I will handle this once the support for those formats will be added
if for you is ok.

> 
> > not a multiple of 128, the division truncates and the hardware uses a
> > wrong stride, causing horizontal banding.
> >
> > Commit ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
> > replaced the open-coded aligned calculation with v4l2_fill_pixfmt(),
> > which sets no alignment, reintroducing the issue.
> >
> > Switch to v4l2_fill_pixfmt_aligned() with RZG2L_CRU_STRIDE_ALIGN when
> > info->has_stride is set. RZ/G2L has no AMnIS register and keeps using
> > v4l2_fill_pixfmt() unchanged.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > Cc: stable@vger.kernel.org
> > Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > ---
> > v2->v3:
> >  - No changes.
> >
> > v1->v2:
> >  - Collected tag
> >  - Add missing Cc stable
> >  - Fix s/commit/Commit/ into commit body
> >
> >  drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > index 69346a585f9f..478264f26466 100644
> > --- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > @@ -860,7 +860,8 @@ static void rzg2l_cru_format_align(struct rzg2l_cru_dev *cru,
> >  	v4l_bound_align_image(&pix->width, 320, info->max_width, 1,
> >  			      &pix->height, 240, info->max_height, 0, 0);
> 
> This doesn't apply on media-committers/next which has
> 
> 	v4l_bound_align_image(&pix->width, 320, info->max_width, 1,
> 			      &pix->height, 240, info->max_height, 2, 0);
> 
> in this line.
> 
> What have I missed ?

Mmmm my fault I errenously have [2]
on top of my local media-committers/next tree.

Will fix that in v4

[1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20260624104153.798953-3-tommaso.merciai.xr@bp.renesas.com/
[2] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20260521131911.92845-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

Kind Regards,
Tommaso

> 
> >
> > -	v4l2_fill_pixfmt(pix, pix->pixelformat, pix->width, pix->height);
> > +	v4l2_fill_pixfmt_aligned(pix, pix->pixelformat, pix->width, pix->height,
> > +				 info->has_stride ? RZG2L_CRU_STRIDE_ALIGN : 1);
> 
> Rebasing apart, this seems correct
> 
> Reviewed-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>
> 
> Thanks
>   j
> 
> >
> >  	dev_dbg(cru->dev, "Format %ux%u bpl: %u size: %u\n",
> >  		pix->width, pix->height, pix->bytesperline, pix->sizeimage);
> > --
> > 2.54.0
> >
> >

Patchew 2.1-devel-ea86937

© 2016 - 2026 Red Hat, Inc.