[PATCH 4.19 100/125] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

Greg Kroah-Hartman
2020-09-01T16:50:17Z

From: Ding Hui <dinghui@sangfor.com.cn>

commit f1ec7ae6c9f8c016db320e204cb519a1da1581b8 upstream.

Some device drivers call libusb_clear_halt when target ep queue
is not empty. (eg. spice client connected to qemu for usb redir)

Before commit f5249461b504 ("xhci: Clear the host side toggle
manually when endpoint is soft reset"), that works well.
But now, we got the error log:

EP not empty, refuse reset

xhci_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
bit still set

So all the subsequent urb sumbits to the ep will fail with the
warn log:

Can't enqueue URB while manually clearing toggle

We need to clear ep_state EP_SOFT_CLEAR_TOGGLE bit after
xhci_endpoint_reset, even if it failed.

Fixes: f5249461b504 ("xhci: Clear the host side toggle manually when endpoint is soft reset")
Cc: stable <stable@vger.kernel.org> # v4.17+
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200821091549.20556-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/host/xhci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3154,10 +3154,11 @@ static void xhci_endpoint_reset(struct u

wait_for_completion(cfg_cmd->completion);

- ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
xhci_free_command(xhci, cfg_cmd);
cleanup:
xhci_free_command(xhci, stop_cmd);
+ if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
+ ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
}

static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,