xhci: Remove "FIXME - check all the stream rings for pending cancellations"

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@redhat.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 2853b2fb57e2b03f3047476c555feeae0a3247ee..4e1c34f45b52cc118eb20c13263a17fa052650d0 100644 (file)
--- 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))