From: Laurent Pinchart laurent.pinchart@ideasonboard.com
[ Upstream commit 81f3affa19d6ab0c32aef46b053838219eef7e71 ]
When the uvcvideo driver encounters a format descriptor with an unknown format GUID, it creates a corresponding struct uvc_format instance with the fcc field set to 0. Since commit 50459f103edf ("media: uvcvideo: Remove format descriptions"), the driver relies on the V4L2 core to provide the format description string, which the V4L2 core can't do without a valid 4CC. This triggers a WARN_ON.
As a format with a zero 4CC can't be selected, it is unusable for applications. Ignore the format completely without creating a uvc_format instance, which fixes the warning.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217252 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2180107
Fixes: 50459f103edf ("media: uvcvideo: Remove format descriptions") Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Ricardo Ribalda ribalda@chromium.org Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/uvc/uvc_driver.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index 7aefa76a42b31..d631ce4f9f7bb 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -251,14 +251,17 @@ static int uvc_parse_format(struct uvc_device *dev, /* Find the format descriptor from its GUID. */ fmtdesc = uvc_format_by_guid(&buffer[5]);
- if (fmtdesc != NULL) { - format->fcc = fmtdesc->fcc; - } else { + if (!fmtdesc) { + /* + * Unknown video formats are not fatal errors, the + * caller will skip this descriptor. + */ dev_info(&streaming->intf->dev, "Unknown video format %pUl\n", &buffer[5]); - format->fcc = 0; + return 0; }
+ format->fcc = fmtdesc->fcc; format->bpp = buffer[21];
/* @@ -675,7 +678,7 @@ static int uvc_parse_streaming(struct uvc_device *dev, interval = (u32 *)&frame[nframes];
streaming->format = format; - streaming->nformats = nformats; + streaming->nformats = 0;
/* Parse the format descriptors. */ while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE) { @@ -689,7 +692,10 @@ static int uvc_parse_streaming(struct uvc_device *dev, &interval, buffer, buflen); if (ret < 0) goto error; + if (!ret) + break;
+ streaming->nformats++; frame += format->nframes; format++;