From mboxrd@z Thu Jan  1 00:00:00 1970
From: Clemens Ladisch <clemens@ladisch.de>
Subject: Re: [PATCH] USB-sound: prevent kernel panic on
	disconnect
Date: Thu, 17 Feb 2011 14:52:08 +0100
Message-ID: <4D5D2808.7060206@ladisch.de>
References: <Pine.LNX.4.44L0.1102111737280.13739-100000@netrider.rowland.org>
	<4D58EDA9.2020805@ladisch.de> <s5hoc6ejz2j.wl%tiwai@suse.de>
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To: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: alsa-devel@alsa-project.org, Takashi Iwai <tiwai@suse.de>, linux-usb@vger.kernel.org, bossart.nospam@gmail.com, Alan Stern <stern@rowland.harvard.edu>, Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
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Sarah Sharp wrote:
> On Mon, Feb 14, 2011 at 06:39:00PM +0100, Takashi Iwai wrote:
> > Clemens Ladisch wrote:
> > > There seems to be a race between snd_usb_pcm_close() and
> > > snd_usb_stream_disconnect().  I think a mutex taken by both functions
> > > should fix this; and all functions that check 'shutdown' probably need
> > > serializing.
> > 
> > Or, rather make sure that snd_usb_release_substreams() is finished
> > before PCM close; actually it should be called in hw_free callback,
> > but currently it's skipped by the shutdown flag check.  I guess this
> > check isn't right.
> > 
> > The serialization of shutdown check is a good point, but this won't
> > hit actual bugs, I suppose.
> 
> Ok.  I don't have the audio expertise to make a patch; can you or
> Clemens make one for Pierre to try out?

I'll try to make a patch until tomorrow.


Regards,
Clemens