Hi James, Thank you for the patch. On Sun, Nov 14, 2021 at 01:52:36AM -0700, James Hilliard wrote: > Some uvc devices appear to require the maximum allowed USB timeout > for GET_CUR/SET_CUR requests. Could you list the devices that you know about which require this change ? > So lets just bump the UVC control timeout to 5 seconds which is the > same as the usb ctrl get/set defaults: > USB_CTRL_GET_TIMEOUT 5000 > USB_CTRL_SET_TIMEOUT 5000 The USB specification (section 9.2.6.4) requires the device to send the first data packet within 500ms of reception of the request. A 500ms timeout may thus be a bit too short for compliant devices, but 5000ms seems to be a very large margin. I'm wondering if it would make sense to go for a lower value. > Fixes: > Failed to query (GET_CUR) UVC control 11 on unit 2: -110 (exp. 1). > Failed to query (SET_CUR) UVC control 3 on unit 2: -110 (exp. 2). > > Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx> > --- > drivers/media/usb/uvc/uvcvideo.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index fd4f5ef47dfb..583c51ac3eec 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -189,7 +189,7 @@ > /* Maximum status buffer size in bytes of interrupt URB. */ > #define UVC_MAX_STATUS_SIZE 16 > > -#define UVC_CTRL_CONTROL_TIMEOUT 500 > +#define UVC_CTRL_CONTROL_TIMEOUT 5000 > #define UVC_CTRL_STREAMING_TIMEOUT 5000 > > /* Maximum allowed number of control mappings per device */ -- Regards, Laurent Pinchart
