Commit 0c74d232 authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
Browse files

xhci: Avoid queuing redundant Stop Endpoint command for stalled endpoint 



If EP_STALLED flag is set in xhci_urb_dequeue(), without EP_HALTED or
SET_DEQ_PENDING flags, then the endpoint is in stopped state and the
cancelled URB can be given back immediately withouth queueing
a 'stop endpoint' command.

Without this change the cancelled URB would eventually be given back
in the 'context state error' completion path of the 'stop endpoint'
command. This is not optimal.

For this improvement to work the EP_STALLED flag must be cleared with
xhci lock held.

Suggested-by: default avatarMichal Pecio <michal.pecio@gmail.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250311154551.4035726-2-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 525b139f

drivers/usb/host/xhci.c

+5 −3
Original line number Diff line number Diff line
@@ -1773,8 +1773,8 @@ static int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) 
		goto done;

	}



	/* In this case no commands are pending but the endpoint is stopped */

	if (ep->ep_state & EP_CLEARING_TT) {

	/* In these cases no commands are pending but the endpoint is stopped */

	if (ep->ep_state & (EP_CLEARING_TT | EP_STALLED)) {

		/* and cancelled TDs can be given back right away */

		xhci_dbg(xhci, "Invalidating TDs instantly on slot %d ep %d in state 0x%x\n",

				urb->dev->slot_id, ep_index, ep->ep_state);
@@ -3211,10 +3211,12 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd, 
		return;



	ep = &vdev->eps[ep_index];



	spin_lock_irqsave(&xhci->lock, flags);



	ep->ep_state &= ~EP_STALLED;



	/* Bail out if toggle is already being cleared by a endpoint reset */

	spin_lock_irqsave(&xhci->lock, flags);

	if (ep->ep_state & EP_HARD_CLEAR_TOGGLE) {

		ep->ep_state &= ~EP_HARD_CLEAR_TOGGLE;

		spin_unlock_irqrestore(&xhci->lock, flags);