linux-kernel - [PATCH 1/4] usb: xhci: remove unnecessary second abort try

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Date:   Fri, 23 Dec 2016 14:52:55 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Mathias Nyman <mathias.nyman@...ux.intel.com>
Cc:     linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 1/4] usb: xhci: remove unnecessary second abort try

The second try was a workaround for (what we thought was) command
ring failing to stop in the first place. But this turns out to be
due to the race that we have fixed(see "xhci: Fix race related to
abort operation"). With that fix, it is time to remove the second
try.

Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
 drivers/usb/host/xhci-ring.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 2f4ea21..e3bcf6d 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -343,19 +343,11 @@ static int xhci_abort_cmd_ring(struct xhci_hcd *xhci, unsigned long *flags)
 	ret = xhci_handshake(&xhci->op_regs->cmd_ring,
 			CMD_RING_RUNNING, 0, 5 * 1000 * 1000);
 	if (ret < 0) {
-		/* we are about to kill xhci, give it one more chance */
-		xhci_write_64(xhci, temp_64 | CMD_RING_ABORT,
-			      &xhci->op_regs->cmd_ring);
-		udelay(1000);
-		ret = xhci_handshake(&xhci->op_regs->cmd_ring,
-				     CMD_RING_RUNNING, 0, 3 * 1000 * 1000);
-		if (ret < 0) {
-			xhci_err(xhci, "Stopped the command ring failed, "
-				 "maybe the host is dead\n");
-			xhci->xhc_state |= XHCI_STATE_DYING;
-			xhci_halt(xhci);
-			return -ESHUTDOWN;
-		}
+		xhci_err(xhci,
+			 "Stop command ring failed, maybe the host is dead\n");
+		xhci->xhc_state |= XHCI_STATE_DYING;
+		xhci_halt(xhci);
+		return -ESHUTDOWN;
 	}
 	/*
 	 * Writing the CMD_RING_ABORT bit should cause a cmd completion event,
-- 
2.1.4