This patch (as1632) fixes a bug in ehci-hcd. The USB core uses urb->hcpriv to determine whether or not an URB is active; host controller drivers are supposed to set this pointer to a non-NULL value when an URB is queued. However ehci-hcd sets it to NULL for isochronous URBs, which defeats the check in usbcore. In itself this isn't a big deal. But people have recently found that certain sequences of actions will cause the snd-usb-audio driver to reuse URBs without waiting for them to complete. In the absence of proper checking by usbcore, the URBs get added to their endpoint list twice. This leads to list corruption and a system freeze. The patch makes ehci-hcd assign a meaningful value to urb->hcpriv for isochronous URBs. Improving robustness always helps. Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Reported-by: Artem S. Tashkinov <t.artem@xxxxxxxxx> Reported-by: Christof Meerwald <cmeerw@xxxxxxxxxx> CC: <stable@xxxxxxxxxxxxxxx> --- drivers/usb/host/ehci-sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: usb-3.7/drivers/usb/host/ehci-sched.c =================================================================== --- usb-3.7.orig/drivers/usb/host/ehci-sched.c +++ usb-3.7/drivers/usb/host/ehci-sched.c @@ -1632,7 +1632,7 @@ static void itd_link_urb( /* don't need that schedule data any more */ iso_sched_free (stream, iso_sched); - urb->hcpriv = NULL; + urb->hcpriv = stream; ++ehci->isoc_count; enable_periodic(ehci); @@ -2031,7 +2031,7 @@ static void sitd_link_urb( /* don't need that schedule data any more */ iso_sched_free (stream, sched); - urb->hcpriv = NULL; + urb->hcpriv = stream; ++ehci->isoc_count; enable_periodic(ehci); -- 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
