From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH]usx2y: prevent oops & dead keyboard on hot usb unplugging Date: Fri, 15 Apr 2005 16:16:53 +0200 Message-ID: References: <20050415135925.86800.qmail@web26502.mail.ukl.yahoo.com> Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <20050415135925.86800.qmail@web26502.mail.ukl.yahoo.com> Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: karsten wiese Cc: Lee Revell , Clemens Ladisch , Devel Alsa List-Id: alsa-devel@alsa-project.org At Fri, 15 Apr 2005 15:59:25 +0200 (CEST), karsten wiese wrote: > > > --- Lee Revell wrote: > > On Thu, 2005-04-14 at 20:59 +0200, karsten wiese wrote: > > > Hi Clemens & Takashi > > > > > > Please commit the patch. > > > > Is the ALSA in kernel 2.6.11 affected? If so, this > > Think so, yes. The keyboard dead effect + described oops > has been around for quiet a long time. > (There is a lkml mail from yesterday about an usb-cellphone > setup, > where the same oops + dead keyboard happens also: > http://marc.theaimsgroup.com/?i=<20050414230621.49663f75.vsu%20()%20altlinux%20!%20ru> > ) > There is also an alsa-bug with snd-usb-audio in the > bugbase. > Clemens seams not to be convinced about this aproach yet. > maybe 'cause the comment of snd_card_free_in_thread > explicitly states that its the one to be called for > hotplug: > /** > * snd_card_free_in_thread - call snd_card_free() in > thread > * @card: soundcard structure > * > * This function schedules the call of snd_card_free() > function in a > * work queue. When all devices are released (non-busy), > the work > * is woken up and calls snd_card_free(). > * > * When a card can be disconnected at any time by hotplug > service, > * this function should be used in disconnect (or detach) > callback > * instead of calling snd_card_free() directly. > * > * Returns - zero otherwise a negative error code if the > start of thread failed. > */ > > Also I remember , that snd_card_free didn't work ok when i > used it in the first implementations of usx2y-module some 2 > years ago. > but that was on kernel 2.4.something....... > maybe above comment is from kernel 2.4 also and the hotplug > system has changed ? anybody? Might be. To be sure, check whether the release fops is called properly before you calling snd_card_free(). Takashi ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click