Re: Logitech HD Webcam C525 does not work when connected to USB 2port, works on USB 3

From: Frederik Himpe
Date: Wed Jul 04 2012 - 16:19:27 EST


On Wed, 2012-07-04 at 14:42 -0400, Alan Stern wrote:
> On Wed, 4 Jul 2012, Frederik Himpe wrote:
>
> > > What happens if you disable USB runtime suspend on the affected system?
> > > Windows tends not to use it.
> >
> > It appears to make a difference, but it still does not work perfectly.
> >
> > I disabled autosuspend like this:
> > root@piranha:/sys# for i in $(find -name autosuspend); do echo 0 > $i; done
>
> That doesn't disable autosuspend. The proper way is:
>
> echo on >/sys/bus/usb/devices/.../power/control
>
> where you fill in the "..." with the directory name for the webcam.

usb trace from trying mplayer a few times after disabling autosuspend:

ffff880415761ec0 897158138 S Ii:1:081:7 -115:128 16 <
ffff8803c49ec800 897158252 S Co:1:081:0 s 21 01 0100 0003 001a 26 = 01000101 15160500 00000000 00000000 00000000 00000000 0000
ffff8803c49ec800 897162252 C Co:1:081:0 -71 0
ffff8803c49ec800 897162388 S Co:1:081:0 s 01 0b 0000 0003 0000 0
ffff8803c49ec800 897166377 C Co:1:081:0 -71 0
ffff880415761ec0 897166486 C Ii:1:081:7 -2:128 0
ffff880415761ec0 897844606 S Ii:1:081:7 -115:128 16 <
ffff8803c49ec800 897844749 S Co:1:081:0 s 21 01 0100 0003 001a 26 = 01000101 15160500 00000000 00000000 00000000 00000000 0000
ffff8803c49ec800 897848746 C Co:1:081:0 -71 0
ffff8803c49ec800 897848879 S Co:1:081:0 s 01 0b 0000 0003 0000 0
ffff8803c49ec800 897852873 C Co:1:081:0 -71 0
ffff880415761ec0 897852965 C Ii:1:081:7 -2:128 16 = 0000e83f 335dbc5f f438be84 08004500
ffff880415761ec0 898444380 S Ii:1:081:7 -115:128 16 <
ffff8803c49ecd40 898444471 S Co:1:081:0 s 21 01 0100 0003 001a 26 = 01000101 15160500 00000000 00000000 00000000 00000000 0000
ffff8803c49ecd40 898448507 C Co:1:081:0 -71 0
ffff8803c49ecd40 898448639 S Co:1:081:0 s 01 0b 0000 0003 0000 0
ffff8803c49ecd40 898452616 C Co:1:081:0 -71 0
ffff880415761ec0 898452722 C Ii:1:081:7 -2:128 0
ffff880415761ec0 899007841 S Ii:1:081:7 -115:128 16 <
ffff8803c49ec800 899007939 S Co:1:081:0 s 21 01 0100 0003 001a 26 = 01000101 15160500 00000000 00000000 00000000 00000000 0000
ffff8803c49ec800 899011863 C Co:1:081:0 -71 0
ffff8803c49ec800 899012005 S Co:1:081:0 s 01 0b 0000 0003 0000 0
ffff8803c49ec800 899015986 C Co:1:081:0 -71 0
ffff880415761ec0 899016082 C Ii:1:081:7 -2:128 0

dmesg contains:
[ 9146.620398] uvcvideo: Failed to set UVC probe control : -71 (exp. 26).

--
Frederik Himpe <fhimpe@xxxxxxxxxx>

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