From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nm3.bt.bullet.mail.ukl.yahoo.com ([217.146.183.201]:37551 "HELO nm3.bt.bullet.mail.ukl.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751295Ab1IXUm1 (ORCPT ); Sat, 24 Sep 2011 16:42:27 -0400 Message-ID: <4E7E40AD.5060206@yahoo.com> Date: Sat, 24 Sep 2011 21:42:21 +0100 From: Chris Rankin MIME-Version: 1.0 To: Michael Hughes CC: linux-media@vger.kernel.org Subject: [PATCH v2] EM28xx - fix deadlock when unplugging and replugging a DVB adapter Content-Type: multipart/mixed; boundary="------------010803040101070609080701" Sender: linux-media-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------010803040101070609080701 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Mauro, Pending the complete rethink about how USB devices manage their resources, I am resubmitting my fix for the PCTV 290e deadlock that occurs with either multiple adapters or when an adapter is replugged. For DVB devices, the device lock must now *not* be held when adding/removing either a device or an extension to the respective lists. (Because em28xx_init_dvb() will want to take the lock instead). Conversely, for Audio-Only devices, the device lock *must* be held when adding/removing either a device or an extension to the respective lists. Signed-off-by: Chris Rankin Cheers, Chris --------------010803040101070609080701 Content-Type: text/x-patch; name="EM28xx-replug-deadlock-2.diff" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="EM28xx-replug-deadlock-2.diff" --- linux/drivers/media/video/em28xx/em28xx-cards.c.orig 2011-09-24 21:25:01.000000000 +0100 +++ linux/drivers/media/video/em28xx/em28xx-cards.c 2011-09-24 21:37:42.000000000 +0100 @@ -3005,9 +3005,7 @@ goto fail; } - mutex_unlock(&dev->lock); em28xx_init_extension(dev); - mutex_lock(&dev->lock); /* Save some power by putting tuner to sleep */ v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_power, 0); @@ -3303,10 +3301,10 @@ em28xx_release_resources(dev); } - mutex_unlock(&dev->lock); - em28xx_close_extension(dev); + mutex_unlock(&dev->lock); + if (!dev->users) { kfree(dev->alt_max_pkt_size); kfree(dev); --------------010803040101070609080701--