6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Ribalda ribalda@chromium.org
commit 758dbc756aad429da11c569c0d067f7fd032bcf7 upstream.
Some devices, like the Grandstream GUV3100 webcam, have an invalid UVC descriptor where multiple entities share the same ID, this is invalid and makes it impossible to make a proper entity tree without heuristics.
We have recently introduced a change in the way that we handle invalid entities that has caused a regression on broken devices.
Implement a new heuristic to handle these devices properly.
Reported-by: Angel4005 ooara1337@gmail.com Closes: https://lore.kernel.org/linux-media/CAOzBiVuS7ygUjjhCbyWg-KiNx+HFTYnqH5+GJhd... Fixes: 0e2ee70291e6 ("media: uvcvideo: Mark invalid entities with id UVC_INVALID_ENTITY_ID") Cc: stable@vger.kernel.org Signed-off-by: Ricardo Ribalda ribalda@chromium.org Reviewed-by: Hans de Goede hansg@kernel.org Signed-off-by: Hans Verkuil hverkuil+cisco@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/usb/uvc/uvc_driver.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
--- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -165,13 +165,26 @@ static struct uvc_entity *uvc_entity_by_
static struct uvc_streaming *uvc_stream_by_id(struct uvc_device *dev, int id) { - struct uvc_streaming *stream; + struct uvc_streaming *stream, *last_stream; + unsigned int count = 0;
list_for_each_entry(stream, &dev->streams, list) { + count += 1; + last_stream = stream; if (stream->header.bTerminalLink == id) return stream; }
+ /* + * If the streaming entity is referenced by an invalid ID, notify the + * user and use heuristics to guess the correct entity. + */ + if (count == 1 && id == UVC_INVALID_ENTITY_ID) { + dev_warn(&dev->intf->dev, + "UVC non compliance: Invalid USB header. The streaming entity has an invalid ID, guessing the correct one."); + return last_stream; + } + return NULL; }