Patch "usb: xhci: lock mutex on xhci_stop" has been added to the 4.2-stable tree

Patch "usb: xhci: lock mutex on xhci_stop" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: xhci: lock mutex on xhci_stop

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-xhci-lock-mutex-on-xhci_stop.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 85ac90f8953a58f6a057b727bc9db97721e3fb8e Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@ti.com>
Date: Mon, 21 Sep 2015 17:46:12 +0300
Subject: usb: xhci: lock mutex on xhci_stop

From: Roger Quadros <rogerq@ti.com>

commit 85ac90f8953a58f6a057b727bc9db97721e3fb8e upstream.

Else it races with xhci_setup_device

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/host/xhci.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -677,8 +677,11 @@ void xhci_stop(struct usb_hcd *hcd)
 	u32 temp;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
+	mutex_lock(&xhci->mutex);
+
 	if (!usb_hcd_is_primary_hcd(hcd)) {
 		xhci_only_stop_hcd(xhci->shared_hcd);
+		mutex_unlock(&xhci->mutex);
 		return;
 	}
 
@@ -717,6 +720,7 @@ void xhci_stop(struct usb_hcd *hcd)
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"xhci_stop completed - status = %x",
 			readl(&xhci->op_regs->status));
+	mutex_unlock(&xhci->mutex);
 }
 
 /*


Patches currently in stable-queue which might be from rogerq@ti.com are

queue-4.2/usb-xhci-exit-early-in-xhci_setup_device-if-we-re-halted-or-dying.patch
queue-4.2/usb-xhci-clear-xhci_state_dying-on-start.patch
queue-4.2/usb-xhci-stop-everything-on-the-first-call-to-xhci_stop.patch
queue-4.2/usb-xhci-lock-mutex-on-xhci_stop.patch