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

[Tommaso Merciai]

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@xxxxxxxxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxxxx/
[2] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20260521131911.92845-1-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

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@xxxxxxxxxxxxxxxx>
> 
> 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
> >
> >