From d4e086141f13379410d75e09b0987aa0bb0ab1d2 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Fri, 29 Jan 2021 15:00:40 +0200 Subject: [PATCH] UPSTREAM: xhci: handle stop endpoint command completion with endpoint in running state. Handle race where a stop endpoint command fails with "context state error" as hardware hasn't actually started the ring yet after a previous urb cancellation completed and restarted the endpoint. Flushing the doorbell write that restart the endpoint reduced these cases, but didn't completely resolve them. Check if the ring is running in the stop endpoint completion handler, and issue a new stop endpoint command in this case. Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20210129130044.206855-24-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 1174d44906d517ddb4f98bbe58a44d4554d0ef90 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus) Signed-off-by: Greg Kroah-Hartman Change-Id: Ie8db9628fd6ccaa07886ec33a89a1ad5872054e1 --- drivers/usb/host/xhci-ring.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 35980773a250..793b01f59e0f 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -983,6 +983,7 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id, struct xhci_ep_ctx *ep_ctx; struct xhci_td *td = NULL; enum xhci_ep_reset_type reset_type; + struct xhci_command *command; if (unlikely(TRB_TO_SUSPEND_PORT(le32_to_cpu(trb->generic.field[3])))) { if (!xhci->devs[slot_id]) @@ -1029,6 +1030,18 @@ static void xhci_handle_cmd_stop_ep(struct xhci_hcd *xhci, int slot_id, /* reset ep, reset handler cleans up cancelled tds */ xhci_handle_halted_endpoint(xhci, ep, 0, td, reset_type); xhci_stop_watchdog_timer_in_irq(xhci, ep); + return; + case EP_STATE_RUNNING: + /* Race, HW handled stop ep cmd before ep was running */ + command = xhci_alloc_command(xhci, false, GFP_ATOMIC); + if (!command) + xhci_stop_watchdog_timer_in_irq(xhci, ep); + + mod_timer(&ep->stop_cmd_timer, + jiffies + XHCI_STOP_EP_CMD_TIMEOUT * HZ); + xhci_queue_stop_endpoint(xhci, command, slot_id, ep_index, 0); + xhci_ring_cmd_db(xhci); + return; default: break;