[PATCH] media: usb: uvc: fill in description for unknown pixelformats

[Hans Verkuil <hverkuil@xxxxxxxxx>]

If the fcc is 0 (indicating an unknown GUID format), then fill in the
description field in ENUM_FMT. Otherwise the V4L2 core will WARN.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Fixes: 50459f103edf ("media: uvcvideo: Remove format descriptions")
---
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 7aefa76a42b3..2f1ced1212cd 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -256,6 +256,9 @@ static int uvc_parse_format(struct uvc_device *dev,
 		} else {
 			dev_info(&streaming->intf->dev,
 				 "Unknown video format %pUl\n", &buffer[5]);
+			snprintf(format->name, sizeof(format->name), "%pUl\n",
+				 &buffer[5]);
+
 			format->fcc = 0;
 		}

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 35453f81c1d9..fc6f9e7d8506 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -713,6 +713,10 @@ static int uvc_ioctl_enum_fmt(struct uvc_streaming *stream,
 	if (format->flags & UVC_FMT_FLAG_COMPRESSED)
 		fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
 	fmt->pixelformat = format->fcc;
+	if (format->name[0])
+		strscpy(fmt->description, format->name,
+			sizeof(fmt->description));
+
 	return 0;
 }

diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 9a596c8d894a..22656755a801 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -264,6 +264,8 @@ struct uvc_format {
 	u32 fcc;
 	u32 flags;

+	char name[32];
+
 	unsigned int nframes;
 	struct uvc_frame *frame;
 };