Messages in this thread | | | Subject | Re: [PATCH 1/1 V2] media: usb: uvc: Fix incorrect timeout for Get Request | From | Jim Lin <> | Date | Fri, 14 Jul 2017 10:11:53 +0800 |
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On 2017年07月11日 03:47, Laurent Pinchart wrote: > Hi Jim, > > Thank you for the patch. > > On Monday 10 Jul 2017 14:43:49 Jim Lin wrote: >> Section 9.2.6.4 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@nvidia.com> > > The patch looks good to me, so > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > but I'm curious, have you noticed issues with some devices in practice ? >
Sometimes this device takes about 360 ms to respond.
usb 1-2: new high-speed USB device number 16 usb 1-2: New USB device found, idVendor=045e, idProduct=0772 usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-2: Product: Microsoft�® LifeCam Studio(TM) usb 1-2: Manufacturer: Microsoft : uvcvideo: Failed to query (GET_DEF) UVC control 2 on unit 4: -110 (exp. 2).
And it will be working well with correct timeout value.
--nvpublic
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