averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-09-22 09:34:56 +02:00
Code Issues Packages Projects Releases Wiki Activity

media: bcm2835-unicam: Fix RGB format / mbus code association

Browse Source 
The Unicam driver is a MIPI-CSI2 Receiver, that can capture RGB 4:4:4,
YCbCr 4:2:2, and raw formats.

RGB 4:4:4 is converted to the MIPI-CSI2 RGB888 video format, and
associated to the MEDIA_BUS_FMT_RGB888_1X24 media bus code.

However, V4L2_PIX_FMT_RGB24 is defined as having its color components in
the R, G and B order, from left to right. MIPI-CSI2 however defines the
RGB888 format with blue first, and that's what MEDIA_BUS_FMT_RGB888_1X24
defines too.

This essentially means that the R and B will be swapped compared to what
V4L2_PIX_FMT_RGB24 defines. The same situation occurs with
V4L2_PIX_FMT_BGR24 being associated to MEDIA_BUS_FMT_BGR888_1X24.

In order to fix the swapped components, we need to change the
association of V4L2_PIX_FMT_BGR24 to MEDIA_BUS_FMT_RGB888_1X24, and of
V4L2_PIX_FMT_RGB24 to MEDIA_BUS_FMT_BGR888_1X24.

Since the media bus code is exposed to userspace, and validated by
unicam's link_validate implementation, we need to explicitly accept (and
warn) the old association still to preserve backward compatibility.

Signed-off-by: Maxime Ripard <mripard@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
This commit is contained in:
Maxime Ripard
2026-03-24 11:58:02 +01:00
committed by Hans Verkuil
parent 7b0288bc05
commit 08f9794d9b
1 changed files with 32 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/media/platform/broadcom/bcm2835-unicam.c
+32 -9
View File
@@ -338,12 +338,12 @@ static const struct unicam_format_info unicam_image_formats[] = {
.csi_dt = MIPI_CSI2_DT_RGB565,
}, {
.fourcc = V4L2_PIX_FMT_RGB24, /* rgb */
.code = MEDIA_BUS_FMT_RGB888_1X24,
.code = MEDIA_BUS_FMT_BGR888_1X24,
.depth = 24,
.csi_dt = MIPI_CSI2_DT_RGB888,
}, {
.fourcc = V4L2_PIX_FMT_BGR24, /* bgr */
.code = MEDIA_BUS_FMT_BGR888_1X24,
.code = MEDIA_BUS_FMT_RGB888_1X24,
.depth = 24,
.csi_dt = MIPI_CSI2_DT_RGB888,
}, {
@@ -2144,22 +2144,45 @@ static int unicam_video_link_validate(struct media_link *link)
const struct v4l2_pix_format *fmt = &node->fmt.fmt.pix;
const struct unicam_format_info *fmtinfo;
fmtinfo = unicam_find_format_by_fourcc(fmt->pixelformat,
UNICAM_SD_PAD_SOURCE_IMAGE);
fmtinfo = unicam_find_format_by_code(format->code,
UNICAM_SD_PAD_SOURCE_IMAGE);
if (WARN_ON(!fmtinfo)) {
ret = -EPIPE;
goto out;
}
if (fmtinfo->code != format->code ||
fmt->height != format->height ||
/*
* Unicam initially associated BGR24 to BGR888_1X24 and RGB24 to
* RGB888_1X24.
*
* In order to allow the applications using the old behaviour to
* run, let's accept the old combination, but warn about it.
*/
if (fmtinfo->fourcc != fmt->pixelformat) {
if ((fmt->pixelformat == V4L2_PIX_FMT_BGR24 &&
format->code == MEDIA_BUS_FMT_BGR888_1X24) ||
(fmt->pixelformat == V4L2_PIX_FMT_RGB24 &&
format->code == MEDIA_BUS_FMT_RGB888_1X24)) {
dev_warn_once(node->dev->dev,
"Incorrect pixel format %p4cc for 0x%04x. Fix your application to use %p4cc.\n",
&fmt->pixelformat, format->code, &fmtinfo->fourcc);
} else {
dev_dbg(node->dev->dev,
"image: format mismatch: 0x%04x <=> %p4cc\n",
format->code, &fmt->pixelformat);
ret = -EPIPE;
goto out;
}
}
if (fmt->height != format->height ||
fmt->width != format->width ||
fmt->field != format->field) {
dev_dbg(node->dev->dev,
"image: (%u x %u) 0x%08x %s != (%u x %u) 0x%08x %s\n",
fmt->width, fmt->height, fmtinfo->code,
"image: (%u x %u) %s != (%u x %u) %s\n",
fmt->width, fmt->height,
v4l2_field_names[fmt->field],
format->width, format->height, format->code,
format->width, format->height,
v4l2_field_names[format->field]);
ret = -EPIPE;
}