[PATCH 2/2] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement

From: Tommaso Merciai

Date: Wed Jun 24 2026 - 06:44:48 EST


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.

Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
---
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