When the device stalls an endpoint, current TD is assigned -EPIPE
status and Reset Endpoint is queued. If a Stop Endpoint is pending
at the time, it will run before Reset Endpoint and fail due to the
stall. Its handler will change TD's status to -EPROTO before Reset
Endpoint handler runs and initiates giveback.
Check if the stall has already been handled and don't try to do it
again. Since xhci_handle_halted_endpoint() performs this check too,
not overwriting td->status is the only difference.
I haven't seen this case yet, but I have seen a related one where
the xHC has already executed Reset Endpoint, EP Context state is
now Stopped and EP_HALTED is set. If the xHC took a bit longer to
execute Reset Endpoint, said case would become this one.
Signed-off-by: Michal Pecio <michal.pecio@xxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9e4940220252..28ebc0fc5bc2 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1215,7 +1215,14 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id,
*/
switch (GET_EP_CTX_STATE(ep_ctx)) {
case EP_STATE_HALTED:
- xhci_dbg(xhci, "Stop ep completion raced with stall, reset ep\n");
+ xhci_dbg(xhci, "Stop ep completion raced with stall\n");
+ /*
+ * If the halt happened before Stop Endpoint failed, its transfer event
+ * should have already been handled and Reset Endpoint should be pending.
+ */
+ if (ep->ep_state & EP_HALTED)
+ goto reset_done;
+
if (ep->ep_state & EP_HAS_STREAMS) {
reset_type = EP_SOFT_RESET;
} else {
@@ -1226,8 +1233,11 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id,
}
/* reset ep, reset handler cleans up cancelled tds */
err = xhci_handle_halted_endpoint(xhci, ep, td, reset_type);
+ xhci_dbg(xhci, "Stop ep completion resetting ep, status %d\n", err);
if (err)
break;
+reset_done:
+ /* Reset EP handler will clean up cancelled TDs */
ep->ep_state &= ~EP_STOP_CMD_PENDING;
return;
case EP_STATE_STOPPED:
--
2.48.1
