From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Takashi Iwai Subject: [ 18/22] ALSA: usb-audio: Fix regression by disconnection-race-fix patch Date: Thu, 24 Jan 2013 13:15:39 -0800 Message-Id: <20130124211510.505607351@linuxfoundation.org> In-Reply-To: <20130124211504.701368763@linuxfoundation.org> References: <20130124211504.701368763@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai [NOTE: the regression below is found only in 3.2-3.4 stable trees, so there is no upstream commit corresponding to this patch] The recent fix for the race at disconnection of usb-audio devices (upstream commit 978520b7) triggers Oops when a device is unplugged while playing on 3.2 and 3.4 kernels. The culprit is that the shutdown flag check was wrongly added around the urb deactivation code snippet. The urb deactivation code has to be performed even after the device disconnected. Otherwise it remains undead and pokes the wild access in the end. The regression fix is simply reverting the shutdown flag check in that code. Reported-and-tested-by: Chris J Arges Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/endpoint.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -148,10 +148,8 @@ void snd_usb_release_substream_urbs(stru int i; /* stop urbs (to be sure) */ - if (!subs->stream->chip->shutdown) { - deactivate_urbs(subs, force, 1); - wait_clear_urbs(subs); - } + deactivate_urbs(subs, force, 1); + wait_clear_urbs(subs); for (i = 0; i < MAX_URBS; i++) release_urb_ctx(&subs->dataurb[i]);