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From:   Tao Wang <wat@codeaurora.org>
To:     quic_wat@quicinc.com, linyyuan@qti.qualcomm.com,
        hongwus@qti.qualcomm.com, zhijunw@qti.qualcomm.com,
        wat@codeaurora.org
Cc:     Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org (open list:USB XHCI DRIVER),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] usb: xhci-ring: USB SSD may fail to unmount if disconnect during data transferring.
Date:   Thu, 12 Aug 2021 20:02:07 +0800
Message-Id: <1628769727-45046-1-git-send-email-wat@codeaurora.org>
Precedence: bulk

From: Tao Wang <quic_wat@quicinc.com>

it stuck in usb_kill_urb() due to urb use_count will not become zero,
this means urb giveback is not happen.
in xhci_handle_cmd_set_deq() will giveback urb if td's cancel_status
equal to TD_CLEARING_CACHE,
but in xhci_invalidate_cancelled_tds(), only last canceled td's
cancel_status change to TD_CLEARING_CACHE,
thus giveback only happen to last urb.

this change set all cancelled_td's cancel_status to TD_CLEARING_CACHE
rather than the last one, so all urb can giveback.

Signed-off-by: Tao Wang <quic_wat@quicinc.com>
---
 drivers/usb/host/xhci-ring.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 8fea44b..c7dd7c0 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -960,19 +960,19 @@ static int xhci_invalidate_cancelled_tds(struct xhci_virt_ep *ep)
 			td_to_noop(xhci, ring, td, false);
 			td->cancel_status = TD_CLEARED;
 		}
-	}
-	if (cached_td) {
-		cached_td->cancel_status = TD_CLEARING_CACHE;
-
-		err = xhci_move_dequeue_past_td(xhci, slot_id, ep->ep_index,
-						cached_td->urb->stream_id,
-						cached_td);
-		/* Failed to move past cached td, try just setting it noop */
-		if (err) {
-			td_to_noop(xhci, ring, cached_td, false);
-			cached_td->cancel_status = TD_CLEARED;
+		if (cached_td) {
+			cached_td->cancel_status = TD_CLEARING_CACHE;
+
+			err = xhci_move_dequeue_past_td(xhci, slot_id, ep->ep_index,
+							cached_td->urb->stream_id,
+							cached_td);
+			/* Failed to move past cached td, try just setting it noop */
+			if (err) {
+				td_to_noop(xhci, ring, cached_td, false);
+				cached_td->cancel_status = TD_CLEARED;
+			}
+			cached_td = NULL;
 		}
-		cached_td = NULL;
 	}
 	return 0;
 }
-- 
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