[PATCH 13/15] usb: xhci: Allow context state errors when halting an endpoint

[Ahmad Fatoum]

This ports U-Boot commit 6f64f0ae230f9e8f68c5d9bf56ffee438fa60a6a:

| Author:     Hector Martin <marcan at marcan.st>
| AuthorDate: Sun Oct 29 15:37:40 2023 +0900
|
| usb: xhci: Allow context state errors when halting an endpoint
|
| There is a race where an endpoint may halt by itself while we are trying
| to halt it, which results in a context state error. See xHCI 4.6.9 which
| mentions this case.
|
| This also avoids BUGging when we attempt to stop an endpoint which was
| already stopped to begin with, which is probably a bug elsewhere but
| not a good reason to crash.
|
| Signed-off-by: Hector Martin <marcan at marcan.st>
| Reviewed-by: Marek Vasut <marex at denx.de>

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/usb/host/xhci-ring.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 23357a882538..1b9a5b7867e0 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -550,6 +550,7 @@ static void abort_td(struct usb_device *udev, int ep_index)
 	struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
 	struct xhci_ring *ring =  ctrl->devs[udev->slot_id]->eps[ep_index].ring;
 	union xhci_trb *event;
+	xhci_comp_code comp;
 	trb_type type;
 	dma_addr_t addr;
 	u32 field;
@@ -578,10 +579,11 @@ static void abort_td(struct usb_device *udev, int ep_index)
 		dev_warn(ctrl->dev, "abort_td: Expected a TRB_TRANSFER TRB first\n");
 	}
 
+	comp = GET_COMP_CODE(le32_to_cpu(event->event_cmd.status));
 	BUG_ON(type != TRB_COMPLETION ||
 		TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
-		!= udev->slot_id || GET_COMP_CODE(le32_to_cpu(
-	        event->event_cmd.status)) != COMP_SUCCESS);
+		!= udev->slot_id || (comp != COMP_SUCCESS && comp
+		!= COMP_CTX_STATE));
 	xhci_acknowledge_event(ctrl);
 
 	addr = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
-- 
2.39.2