Revert "xhci: Prevent early endpoint restart when handling STALL errors."

This reverts commit 860f5d0.

Paul Menzel reported that the two EP_STALLED patches in 6.15-rc1 cause
regression. Turns out that the new flag may never get cleared after
reset-resume, preventing xhci from restarting the endpoint.

Revert this to take a proper look at it.

Link: https://lore.kernel.org/linux-usb/84b400f8-2943-44e0-8803-f3aac3b670af@molgen.mpg.de
cc: Paul Menzel <pmenzel@molgen.mpg.de>
cc: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250410151828.2868740-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: matnyman

drivers/usb/host/xhci-ring.c

@@ -561,8 +561,8 @@ 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 | SET_DEQ_PENDING | EP_HALTED |
-			EP_CLEARING_TT | EP_STALLED))
+	if ((ep_state & EP_STOP_CMD_PENDING) || (ep_state & SET_DEQ_PENDING) ||
+	    (ep_state & EP_HALTED) || (ep_state & EP_CLEARING_TT))
 		return;
 
 	trace_xhci_ring_ep_doorbell(slot_id, DB_VALUE(ep_index, stream_id));
@@ -2573,9 +2573,6 @@ 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;

drivers/usb/host/xhci.c

@@ -1605,11 +1605,6 @@ 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:
@@ -3208,7 +3203,6 @@ 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);

drivers/usb/host/xhci.h

@@ -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)	/* Halted host ep handling */
+#define EP_HALTED		(1 << 1)	/* For stall 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)
@@ -675,7 +675,6 @@ 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;