[PATCH v5 1/5] media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement

[Tommaso Merciai]

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.

Round bytesperline up to RZG2L_CRU_STRIDE_ALIGN and recompute
sizeimage when info->has_stride is set. RZ/G2L has no AMnIS register
and keeps the values from v4l2_fill_pixfmt() unchanged.

Fixes: ace92ccef0c9 ("media: platform: rzg2l-cru: Use v4l2_fill_pixfmt()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
---
v4->v5:
 - New patch.

 drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
index 5185a547461d..91eda5034248 100644
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
@@ -851,6 +851,11 @@ static void rzg2l_cru_format_align(struct rzg2l_cru_dev *cru,
 
 	v4l2_fill_pixfmt(pix, pix->pixelformat, pix->width, pix->height);
 
+	if (info->has_stride) {
+		pix->bytesperline = ALIGN(pix->bytesperline, RZG2L_CRU_STRIDE_ALIGN);
+		pix->sizeimage = pix->bytesperline * pix->height;
+	}
+
 	dev_dbg(cru->dev, "Format %ux%u bpl: %u size: %u\n",
 		pix->width, pix->height, pix->bytesperline, pix->sizeimage);
 }
-- 
2.54.0