[PATCH v2 0/4] media: rzg2l-cru: Fix DMA stride alignment

[PATCH v2 0/4] media: rzg2l-cru: Fix DMA stride alignment

[Tommaso Merciai]

Dear All,

While testing ov5645 + RZ/G3E we found out that the UYVY8_2X8/2592x1944
is broken. The issue is that the CRU DMA engine requires the line stride
to be a multiple of 128 bytes (RZG2L_CRU_STRIDE_ALIGN). v4l2_fill_pixfmt()
sets bytesperline as width * bytes_per_pixel with no alignment, so for
widths whose natural stride is not 128-byte aligned the hardware silently
rounds up, causing a mismatch that produces visible horizontal banding in
the captured image.

Tested using:

media-ctl -d /dev/media0 --set-v4l2 '"ov5645 0-003c":0[fmt:UYVY8_2X8/2592x1944 field:none]'
media-ctl -d /dev/media0 --set-v4l2 '"csi-16000400.csi2":0[fmt:UYVY8_2X8/2592x1944]'
media-ctl -d /dev/media0 --set-v4l2 '"cru-ip-16000000.video":0[fmt:UYVY8_2X8/2592x1944]'

v4l2-ctl -d /dev/video0 --verbose --set-fmt-video=width=2592,height=1944,pixelformat=UYVY --stream-mmap --stream-count=100 --stream-to=./frame.raw
gst-launch-1.0 v4l2src device=/dev/video0 blocksize=76800 io-mode=dmabuf num-buffers=200 ! video/x-raw,format=UYVY,width=2592,height=1944 !  videoconvert ! queue ! waylandsink sync=false

This patch fix the issue.

Kind Regards,
Tommaso

v1->v2:
 - PATCH 3/4: Move v4l2_fill_pixfmt() into v4l2-common.h as inline wrapper
   Add v4l2_fill_pixfmt_aligned() helper documentation.
 - PATCH 4/4: Collected tag, add missing Cc stable, fix s/commit/Commit/
   into commit body.

Tommaso Merciai (4):
  media: v4l2-common: Convert v4l2_fill_pixfmt_mp() to static inline
    wrapper
  media: v4l2-common: Add kernel-doc for v4l2_fill_pixfmt_mp_aligned()
  media: v4l2-common: Add v4l2_fill_pixfmt_aligned() helper
  media: rzg2l-cru: Align bytesperline to hardware DMA stride
    requirement

 .../platform/renesas/rzg2l-cru/rzg2l-video.c  |  3 +-
 drivers/media/v4l2-core/v4l2-common.c         | 20 ++---
 include/media/v4l2-common.h                   | 74 +++++++++++++++++--
 3 files changed, 78 insertions(+), 19 deletions(-)

-- 
2.54.0

[PATCH v2 1/4] media: v4l2-common: Convert v4l2_fill_pixfmt_mp() to static inline wrapper

[Tommaso Merciai]

Convert v4l2_fill_pixfmt_mp() to static inline wrapper: drop the exported
v4l2_fill_pixfmt_mp() function from v4l2-common.c and replace it with
an equivalent static inline in the header that delegates to
v4l2_fill_pixfmt_mp_aligned() with stride_alignment=1.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v1->v2:
 - New patch

 drivers/media/v4l2-core/v4l2-common.c | 8 --------
 include/media/v4l2-common.h           | 9 +++++++--
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 65db7340ad38..54995ba8c20d 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -537,14 +537,6 @@ int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
 }
 EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_mp_aligned);
 
-int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
-			u32 pixelformat, u32 width, u32 height)
-{
-	return v4l2_fill_pixfmt_mp_aligned(pixfmt, pixelformat,
-					   width, height, 1);
-}
-EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_mp);
-
 int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
 		     u32 width, u32 height)
 {
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index edd416178c33..749fe38c134e 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -556,13 +556,18 @@ void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
 				    const struct v4l2_frmsize_stepwise *frmsize);
 int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
 		     u32 width, u32 height);
-int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
-			u32 width, u32 height);
+
 /* @stride_alignment is a power of 2 value in bytes */
 int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
 				u32 pixelformat, u32 width, u32 height,
 				u8 stride_alignment);
 
+static inline int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
+				      u32 pixelformat, u32 width, u32 height)
+{
+	return v4l2_fill_pixfmt_mp_aligned(pixfmt, pixelformat, width, height, 1);
+}
+
 /**
  * v4l2_get_link_freq - Get link rate from transmitter
  *
-- 
2.54.0

[PATCH v2 2/4] media: v4l2-common: Add kernel-doc for v4l2_fill_pixfmt_mp_aligned()

[Tommaso Merciai]

Replace the bare placeholder comment with a full kernel-doc block
documenting all parameters, the function behaviour for both single
memory plane (mem_planes == 1) and multiple memory plane (mem_planes > 1)
formats, and the return value.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v1->v2:
 - New patch

 include/media/v4l2-common.h | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 749fe38c134e..db59dda578f0 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -557,7 +557,32 @@ void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
 int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
 		     u32 width, u32 height);
 
-/* @stride_alignment is a power of 2 value in bytes */
+/**
+ * v4l2_fill_pixfmt_mp_aligned - Fill in a &struct v4l2_pix_format_mplane with
+ *	stride alignment requirements.
+ *
+ * @pixfmt: pointer to the &struct v4l2_pix_format_mplane to be filled
+ * @pixelformat: the V4L2 pixel format (V4L2_PIX_FMT_*)
+ * @width: image width in pixels
+ * @height: image height in pixels
+ * @stride_alignment: stride alignment in bytes; must be a power of 2
+ *
+ * Fills all fields of @pixfmt for the given pixel format, dimensions, and
+ * stride alignment.
+ *
+ * For formats stored in a single memory plane (mem_planes == 1), the
+ * behaviour matches v4l2_fill_pixfmt_aligned(): plane_fmt[0].bytesperline
+ * is set to the primary plane stride rounded up to @stride_alignment, and
+ * per-component alignments are scaled to keep chroma strides consistently
+ * derivable from the luma stride. plane_fmt[0].sizeimage covers all
+ * component planes.
+ *
+ * For formats with multiple memory planes (mem_planes > 1), each plane's
+ * bytesperline is independently rounded up to @stride_alignment, and
+ * sizeimage is set to bytesperline multiplied by the plane height.
+ *
+ * Return: 0 on success, -EINVAL if @pixelformat is unknown.
+ */
 int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
 				u32 pixelformat, u32 width, u32 height,
 				u8 stride_alignment);
-- 
2.54.0

Re: [PATCH v2 2/4] media: v4l2-common: Add kernel-doc for v4l2_fill_pixfmt_mp_aligned()

[Sven Püschel]

Hi Tommaso,

thanks for adding documentation.

On 7/1/26 6:49 PM, Tommaso Merciai wrote:
> Replace the bare placeholder comment with a full kernel-doc block
> documenting all parameters, the function behaviour for both single
> memory plane (mem_planes == 1) and multiple memory plane (mem_planes > 1)
> formats, and the return value.
>
> Signed-off-by: Tommaso Merciai<tommaso.merciai.xr@bp.renesas.com>
> ---
> v1->v2:
>   - New patch
>
>   include/media/v4l2-common.h | 27 ++++++++++++++++++++++++++-
>   1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> index 749fe38c134e..db59dda578f0 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -557,7 +557,32 @@ void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
>   int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
>   		     u32 width, u32 height);
>   
> -/* @stride_alignment is a power of 2 value in bytes */
> +/**
> + * v4l2_fill_pixfmt_mp_aligned - Fill in a &struct v4l2_pix_format_mplane with
> + *	stride alignment requirements.
> + *
> + * @pixfmt: pointer to the &struct v4l2_pix_format_mplane to be filled
> + * @pixelformat: the V4L2 pixel format (V4L2_PIX_FMT_*)
> + * @width: image width in pixels
> + * @height: image height in pixels
> + * @stride_alignment: stride alignment in bytes; must be a power of 2
> + *
> + * Fills all fields of @pixfmt for the given pixel format, dimensions, and
> + * stride alignment.
> + *
> + * For formats stored in a single memory plane (mem_planes == 1), the
> + * behaviour matches v4l2_fill_pixfmt_aligned(): plane_fmt[0].bytesperline
Given that the v4l2_fill_pixfmt_aligned helper is added later in patch 
3, don't you want to move this patch after adding the helper?
> + * is set to the primary plane stride rounded up to @stride_alignment, and
> + * per-component alignments are scaled to keep chroma strides consistently
> + * derivable from the luma stride. plane_fmt[0].sizeimage covers all

No, it's the other way: The strides of all components are aligned to the 
@stride_alignment. To keep the chroma strides consistently derivable 
from the luma stride, strides may be aligned to a multiple of the 
@stride_alignment.

(feel free to use the above if it sounds good)

At least I read your text, as if only the y stride would be rounded up 
to the nearest alignment and for other component strides may be scaled 
down to 1/2 or 1/4 of the alignment. But most of the time the y stride 
will be scaled up (e.g. YUV420 or YUV410) and in rare cases (e.g. 
NV24/42) the component stride is scaled up.

Sincerely
     Sven

> + * component planes.
> + *
> + * For formats with multiple memory planes (mem_planes > 1), each plane's
> + * bytesperline is independently rounded up to @stride_alignment, and
> + * sizeimage is set to bytesperline multiplied by the plane height.
> + *
> + * Return: 0 on success, -EINVAL if @pixelformat is unknown.
> + */
>   int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
>   				u32 pixelformat, u32 width, u32 height,
>   				u8 stride_alignment);

Re: [PATCH v2 2/4] media: v4l2-common: Add kernel-doc for v4l2_fill_pixfmt_mp_aligned()

[Tommaso Merciai]

Hi Sven,
Thanks for your review.

On Fri, Jul 03, 2026 at 02:14:55PM +0200, Sven Püschel wrote:
> Hi Tommaso,
> 
> thanks for adding documentation.
> 
> On 7/1/26 6:49 PM, Tommaso Merciai wrote:
> > Replace the bare placeholder comment with a full kernel-doc block
> > documenting all parameters, the function behaviour for both single
> > memory plane (mem_planes == 1) and multiple memory plane (mem_planes > 1)
> > formats, and the return value.
> > 
> > Signed-off-by: Tommaso Merciai<tommaso.merciai.xr@bp.renesas.com>
> > ---
> > v1->v2:
> >   - New patch
> > 
> >   include/media/v4l2-common.h | 27 ++++++++++++++++++++++++++-
> >   1 file changed, 26 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> > index 749fe38c134e..db59dda578f0 100644
> > --- a/include/media/v4l2-common.h
> > +++ b/include/media/v4l2-common.h
> > @@ -557,7 +557,32 @@ void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
> >   int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
> >   		     u32 width, u32 height);
> > -/* @stride_alignment is a power of 2 value in bytes */
> > +/**
> > + * v4l2_fill_pixfmt_mp_aligned - Fill in a &struct v4l2_pix_format_mplane with
> > + *	stride alignment requirements.
> > + *
> > + * @pixfmt: pointer to the &struct v4l2_pix_format_mplane to be filled
> > + * @pixelformat: the V4L2 pixel format (V4L2_PIX_FMT_*)
> > + * @width: image width in pixels
> > + * @height: image height in pixels
> > + * @stride_alignment: stride alignment in bytes; must be a power of 2
> > + *
> > + * Fills all fields of @pixfmt for the given pixel format, dimensions, and
> > + * stride alignment.
> > + *
> > + * For formats stored in a single memory plane (mem_planes == 1), the
> > + * behaviour matches v4l2_fill_pixfmt_aligned(): plane_fmt[0].bytesperline
> Given that the v4l2_fill_pixfmt_aligned helper is added later in patch 3,
> don't you want to move this patch after adding the helper?

You are correct, thanks.
I will move this after adding the helper in v3.

> > + * is set to the primary plane stride rounded up to @stride_alignment, and
> > + * per-component alignments are scaled to keep chroma strides consistently
> > + * derivable from the luma stride. plane_fmt[0].sizeimage covers all
> 
> No, it's the other way: The strides of all components are aligned to the
> @stride_alignment. To keep the chroma strides consistently derivable from
> the luma stride, strides may be aligned to a multiple of the
> @stride_alignment.
> 
> (feel free to use the above if it sounds good)

Thanks for the clarification.
I will use your suggestion in v3.

Kind Regards,
Tommaso

> 
> At least I read your text, as if only the y stride would be rounded up to
> the nearest alignment and for other component strides may be scaled down to
> 1/2 or 1/4 of the alignment. But most of the time the y stride will be
> scaled up (e.g. YUV420 or YUV410) and in rare cases (e.g. NV24/42) the
> component stride is scaled up.
> 
> Sincerely
>     Sven
> 
> > + * component planes.
> > + *
> > + * For formats with multiple memory planes (mem_planes > 1), each plane's
> > + * bytesperline is independently rounded up to @stride_alignment, and
> > + * sizeimage is set to bytesperline multiplied by the plane height.
> > + *
> > + * Return: 0 on success, -EINVAL if @pixelformat is unknown.
> > + */
> >   int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
> >   				u32 pixelformat, u32 width, u32 height,
> >   				u8 stride_alignment);

[PATCH v2 3/4] media: v4l2-common: Add v4l2_fill_pixfmt_aligned() helper

[Tommaso Merciai]

Add v4l2_fill_pixfmt_aligned(), a variant of v4l2_fill_pixfmt()
that accepts a stride_alignment parameter, mirroring the existing
v4l2_fill_pixfmt_mp() / v4l2_fill_pixfmt_mp_aligned() pair.

v4l2_fill_pixfmt() is refactored to call v4l2_fill_pixfmt_aligned()
with stride_alignment=1, preserving its existing behaviour.

The new helper is needed by drivers whose DMA engine requires the
line stride to be a multiple of a specific value, such as the
Renesas RZ/G3E CRU which requires 128-byte alignment.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v1->v2:
 - Move v4l2_fill_pixfmt() into v4l2-common.h as inline wrapper
 - Add v4l2_fill_pixfmt_aligned() helper documentation.

 drivers/media/v4l2-core/v4l2-common.c | 12 +++++----
 include/media/v4l2-common.h           | 38 +++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 54995ba8c20d..2ce4f1c20fbc 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -537,8 +537,8 @@ int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
 }
 EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_mp_aligned);
 
-int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
-		     u32 width, u32 height)
+int v4l2_fill_pixfmt_aligned(struct v4l2_pix_format *pixfmt, u32 pixelformat,
+			     u32 width, u32 height, u8 stride_alignment)
 {
 	const struct v4l2_format_info *info;
 	int i;
@@ -554,15 +554,17 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
 	pixfmt->width = width;
 	pixfmt->height = height;
 	pixfmt->pixelformat = pixelformat;
-	pixfmt->bytesperline = v4l2_format_plane_stride(info, 0, width, 1);
+	pixfmt->bytesperline = v4l2_format_plane_stride(info, 0, width,
+							stride_alignment);
 	pixfmt->sizeimage = 0;
 
 	for (i = 0; i < info->comp_planes; i++)
 		pixfmt->sizeimage +=
-			v4l2_format_plane_size(info, i, width, height, 1);
+			v4l2_format_plane_size(info, i, width, height,
+					       stride_alignment);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
+EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_aligned);
 
 #ifdef CONFIG_MEDIA_CONTROLLER
 static s64 v4l2_get_link_freq_ctrl(struct v4l2_ctrl_handler *handler,
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index db59dda578f0..7c8cb5a8befd 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -554,8 +554,42 @@ static inline bool v4l2_is_format_bayer(const struct v4l2_format_info *f)
 const struct v4l2_format_info *v4l2_format_info(u32 format);
 void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
 				    const struct v4l2_frmsize_stepwise *frmsize);
-int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
-		     u32 width, u32 height);
+
+/**
+ * v4l2_fill_pixfmt_aligned - Fill in a &struct v4l2_pix_format with stride
+ *	alignment requirements.
+ *
+ * @pixfmt: pointer to the &struct v4l2_pix_format to be filled
+ * @pixelformat: the V4L2 pixel format (V4L2_PIX_FMT_*)
+ * @width: image width in pixels
+ * @height: image height in pixels
+ * @stride_alignment: stride alignment in bytes, must be a power of 2
+ *
+ * Fills all fields of @pixfmt for the given pixel format, dimensions, and
+ * stride alignment. Only formats stored in a single memory plane are
+ * supported; returns -EINVAL for multi-memory-plane formats.
+ *
+ * @pixfmt->bytesperline is set to the stride of the primary (plane 0) plane,
+ * rounded up to a multiple of @stride_alignment. For formats that store
+ * multiple component planes in a single memory buffer (e.g. NV12), the
+ * alignment applied to each component plane's stride is scaled relative to
+ * @stride_alignment so that the chroma stride remains consistently derivable
+ * from the luma stride. @pixfmt->bytesperline therefore reflects only the
+ * primary plane stride.
+ *
+ * @pixfmt->sizeimage is set to the total size in bytes of all component planes.
+ *
+ * Return: 0 on success, -EINVAL if @pixelformat is unknown or uses multiple
+ *	memory planes.
+ */
+int v4l2_fill_pixfmt_aligned(struct v4l2_pix_format *pixfmt, u32 pixelformat,
+			     u32 width, u32 height, u8 stride_alignment);
+
+static inline int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt,
+				   u32 pixelformat, u32 width, u32 height)
+{
+	return v4l2_fill_pixfmt_aligned(pixfmt, pixelformat, width, height, 1);
+}
 
 /**
  * v4l2_fill_pixfmt_mp_aligned - Fill in a &struct v4l2_pix_format_mplane with
-- 
2.54.0

[PATCH v2 4/4] 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.

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>
---
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