On 07/25/2014 11:01 PM, Hans de Goede wrote: > Even though a Set TR deq ptr command operates on a ring, and an endpoint > can have multiple rings, we can have only one Set TR deq ptr command pending. > > When an endpoint with streams halts or is stopped to unlink urbs, there > will only be at most one ring active / one td being executed (the td > stopped_td points to). > > So when we reset the endpoint (for a halt), or the stop command completes, we > will queue one Set TR deq ptr command at most, cancelled urbs on other stream > rings then the one being executed will have there trbs turned to nops, and > once the hcd gets around to execute that stream ring they will be simply > skipped. > > So the SET_DEQ_PENDING flag in the endpoint is sufficient protection against > starting the endpoing before all stream rings are cleaned up. > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/usb/host/xhci-ring.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c > index 77d47c6..493825b 100644 > --- a/drivers/usb/host/xhci-ring.c > +++ b/drivers/usb/host/xhci-ring.c > @@ -327,7 +327,6 @@ void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, > * We don't want to restart any stream rings if there's a set dequeue > * pointer command pending because the device can choose to start any > * stream once the endpoint is on the HW schedule. > - * FIXME - check all the stream rings for pending cancellations. > */ > if ((ep_state & EP_HALT_PENDING) || (ep_state & SET_DEQ_PENDING) || > (ep_state & EP_HALTED)) > Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> -- 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
