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xhci: Prevent early endpoint restart when handling STALL errors.

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Ensure that an endpoint halted due to device STALL is not
restarted before a Clear_Feature(ENDPOINT_HALT) request is sent to
the device.

The host side of the endpoint may otherwise be started early by the
'Set TR Deq' command completion handler which is called if dequeue
is moved past a cancelled or halted TD.

Prevent this with a new flag set for bulk and interrupt endpoints
when a Stall Error is received. Clear it in hcd->endpoint_reset()
which is called after Clear_Feature(ENDPOINT_HALT) is sent.

Also add a debug message if a class driver queues a new URB after the
STALL. Note that class driver might not be aware of the STALL
yet when it submits the URB as URBs are given back in BH.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250306144954.3507700-13-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2025-03-06 16:49:51 +02:00 committed by Greg Kroah-Hartman
parent 9a7f4bc4c8
commit 860f5d0d35
3 changed files with 13 additions and 3 deletions
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7
drivers/usb/host/xhci-ring.c
View File

@ -556,8 +556,8 @@ void xhci_ring_ep_doorbell(struct xhci_hcd *xhci,
* pointer command pending because the device can choose to start any
* stream once the endpoint is on the HW schedule.
*/
if ((ep_state & EP_STOP_CMD_PENDING) || (ep_state & SET_DEQ_PENDING) ||
(ep_state & EP_HALTED) || (ep_state & EP_CLEARING_TT))
if (ep_state & (EP_STOP_CMD_PENDING | SET_DEQ_PENDING | EP_HALTED |
EP_CLEARING_TT | EP_STALLED))
return;
trace_xhci_ring_ep_doorbell(slot_id, DB_VALUE(ep_index, stream_id));
@ -2555,6 +2555,9 @@ static void process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
xhci_handle_halted_endpoint(xhci, ep, td, EP_SOFT_RESET);
return;
case COMP_STALL_ERROR:
ep->ep_state |= EP_STALLED;
break;
default:
/* do nothing */
break;

6
drivers/usb/host/xhci.c
View File

@ -1604,6 +1604,11 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
goto free_priv;
}
/* Class driver might not be aware ep halted due to async URB giveback */
if (*ep_state & EP_STALLED)
dev_dbg(&urb->dev->dev, "URB %p queued before clearing halt\n",
urb);
switch (usb_endpoint_type(&urb->ep->desc)) {
case USB_ENDPOINT_XFER_CONTROL:
@ -3202,6 +3207,7 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
return;
ep = &vdev->eps[ep_index];
ep->ep_state &= ~EP_STALLED;
/* Bail out if toggle is already being cleared by a endpoint reset */
spin_lock_irqsave(&xhci->lock, flags);

3
drivers/usb/host/xhci.h
View File

@ -664,7 +664,7 @@ struct xhci_virt_ep {
unsigned int err_count;
unsigned int ep_state;
#define SET_DEQ_PENDING (1 << 0)
#define EP_HALTED (1 << 1) /* For stall handling */
#define EP_HALTED (1 << 1) /* Halted host ep handling */
#define EP_STOP_CMD_PENDING (1 << 2) /* For URB cancellation */
/* Transitioning the endpoint to using streams, don't enqueue URBs */
#define EP_GETTING_STREAMS (1 << 3)
@ -675,6 +675,7 @@ struct xhci_virt_ep {
#define EP_SOFT_CLEAR_TOGGLE (1 << 7)
/* usb_hub_clear_tt_buffer is in progress */
#define EP_CLEARING_TT (1 << 8)
#define EP_STALLED (1 << 9) /* For stall handling */
/* ---- Related to URB cancellation ---- */
struct list_head cancelled_td_list;
struct xhci_hcd *xhci;