Brian, Working - I appreciate this. I applied this mini-patch to kernel 4.8.1 and confirm that after a few test scans, I now have no problem with the USB Canon scanner. Also seems to have cleared up a puzzling no-input problem I was having with a cheap no-brand USB keyboard/video/mouse switch under 4.8.1. Thanks, Joe On Fri, Oct 14, 2016 at 3:52 PM, Bryan Paluch <bryanpaluch@xxxxxxxxx> wrote: > I've been experiencing similar issues with usb audio headsets. There is an > issue for ubuntu 16.10 here > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1630063 . > > I was able to fix the issue by changing the IO_WATCHDOG_DELAY in ohci-hcd.c > from 250 msec to 275 msec. I suspect that the new timer wheel based timers > in 4.8 have exposed a bug in the ohci driver. Before the io watchdog timer > was set to 250 with 20 msecs of slack time. This is more than likely just a > hacky work around but I'm able to use my usb headphones now. Here's my diff > > diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c > index 1700908..86612ac 100644 > --- a/drivers/usb/host/ohci-hcd.c > +++ b/drivers/usb/host/ohci-hcd.c > @@ -72,7 +72,7 @@ > static const char hcd_name [] = "ohci_hcd"; > > #define STATECHANGE_DELAY msecs_to_jiffies(300) > -#define IO_WATCHDOG_DELAY msecs_to_jiffies(250) > +#define IO_WATCHDOG_DELAY msecs_to_jiffies(275) > > #include "ohci.h" > #include "pci-quirks.h" -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
