Re: [PATCH 1/1 V2] media: usb: uvc: Fix incorrect timeout for Get Request
From: Laurent Pinchart
Date: Mon Jul 10 2017 - 15:47:32 EST
Thank you for the patch.
On Monday 10 Jul 2017 14:43:49 Jim Lin wrote:
> Section 126.96.36.199 of USB 2.0/3.x specification describes that
> "device must be able to return the first data packet to host within
> 500 ms of receipt of the request. For subsequent data packet, if any,
> the device must be able to return them within 500 ms".
> This is to fix incorrect timeout and change it from 300 ms to 500 ms
> to meet the timing specified by specification for Get Request.
> Signed-off-by: Jim Lin <jilin@xxxxxxxxxx>
The patch looks good to me, so
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
but I'm curious, have you noticed issues with some devices in practice ?
> V2: Change patch description
> 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 15e415e..296b69b 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -166,7 +166,7 @@
> /* Maximum status buffer size in bytes of interrupt URB. */
> #define UVC_MAX_STATUS_SIZE 16
> -#define UVC_CTRL_CONTROL_TIMEOUT 300
> +#define UVC_CTRL_CONTROL_TIMEOUT 500
> #define UVC_CTRL_STREAMING_TIMEOUT 5000
> /* Maximum allowed number of control mappings per device */