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Message-ID: <585D15A2.2000909@linux.intel.com>
Date: Fri, 23 Dec 2016 14:16:34 +0200
From: Mathias Nyman <mathias.nyman@...ux.intel.com>
To: Lu Baolu <baolu.lu@...ux.intel.com>
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
stable@...r.kernel.org
Subject: Re: [PATCH 1/1] usb: xhci: hold lock over xhci_abort_cmd_ring()
On 23.12.2016 08:46, Lu Baolu wrote:
> In command timer function, xhci_handle_command_timeout(), xhci->lock
> is unlocked before call into xhci_abort_cmd_ring(). This might cause
> race between the timer function and the event handler.
>
> The xhci_abort_cmd_ring() function sets the CMD_RING_ABORT bit in the
> command register and polling it until the setting takes effect. A stop
> command ring event might be handled between writing the abort bit and
> polling for it. The event handler will restart the command ring, which
> causes the failure of polling, and we ever believed that we failed to
> stop it.
>
> As a bonus, this also fixes some issues of calling functions without
> locking in xhci_handle_command_timeout().
>
Did the same thing, moved the unlock to cover also abort_cmd_ring(),
but this one takes care of locking the command ring cleanup as well
so I'll pick up this instead
-Mathias
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