[PATCH 4/7] xhci: Remove "FIXME - check all the stream rings for pending cancellations"

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Hans de Goede <hdegoede@xxxxxxxxxx>

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>
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
 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 f58856b..5a85605 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))
-- 
1.8.3.2

--
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




[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux