On Tue, 6 Aug 2013, [koi8-r] ����� ������ wrote:
> Hi,
>
> I have Logitech HD Webcam 525 (046d:0826) but its mic works strange. The mic
> is turned off while video works fine. In dmesg I see the following messages
>
> [ 472.079738] cannot submit urb (err = -18)
> [ 472.079748] cannot submit urb (err = -18)
> [ 472.079754] cannot submit urb (err = -18)
> [ 472.079759] cannot submit urb (err = -18)
> [ 472.079783] cannot submit urb (err = -18)
> [ 472.079787] cannot submit urb (err = -18)
> [ 472.079792] cannot submit urb (err = -18)
> [ 472.079797] cannot submit urb (err = -18)
> I have not enough experience to fix it myself but I can help with
> finding a bug and testing fixes. I have also found that the same
> problem exists for Logitech Webcam C310 (046d:081b). The bug is not
> specific for my laptop. I have the same issue on my desktop with both
> cameras.
Does this patch help?
Alan Stern
Index: usb-3.11/drivers/usb/host/ehci-sched.c
===================================================================
--- usb-3.11.orig/drivers/usb/host/ehci-sched.c
+++ usb-3.11/drivers/usb/host/ehci-sched.c
@@ -1391,21 +1391,20 @@ iso_stream_schedule (
/* Behind the scheduling threshold? */
if (unlikely(start < next)) {
+ unsigned now2 = (now - base) & (mod - 1);
/* USB_ISO_ASAP: Round up to the first available slot */
if (urb->transfer_flags & URB_ISO_ASAP)
start += (next - start + period - 1) & -period;
/*
- * Not ASAP: Use the next slot in the stream. If
- * the entire URB falls before the threshold, fail.
+ * Not ASAP: Use the next slot in the stream,
+ * no matter what.
*/
- else if (start + span - period < next) {
- ehci_dbg(ehci, "iso urb late %p (%u+%u < %u)\n",
+ else if (start + span - period < now2) {
+ ehci_dbg(ehci, "iso underrun %p (%u+%u < %u)\n",
urb, start + base,
- span - period, next + base);
- status = -EXDEV;
- goto fail;
+ span - period, now2 + base);
}
}
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