From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756012Ab2HIHbf (ORCPT ); Thu, 9 Aug 2012 03:31:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:40114 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755670Ab2HIHbe (ORCPT ); Thu, 9 Aug 2012 03:31:34 -0400 Date: Thu, 09 Aug 2012 09:31:30 +0200 Message-ID: From: Takashi Iwai To: Thierry Reding Cc: Jaroslav Kysela , David Henningsson , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ALSA: hda - Defer probe when loading patch firmware In-Reply-To: <20120809070813.GA6979@avionic-0098.mockup.avionic-design.de> References: <1344494723-6827-1-git-send-email-thierry.reding@avionic-design.de> <20120809070813.GA6979@avionic-0098.mockup.avionic-design.de> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.1 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Thu, 9 Aug 2012 09:08:13 +0200, Thierry Reding wrote: > > On Thu, Aug 09, 2012 at 08:57:13AM +0200, Takashi Iwai wrote: > > At Thu, 9 Aug 2012 08:45:23 +0200, > > Thierry Reding wrote: > > > > > > Recent changes to the firmware loading helpers cause drivers to stall > > > when firmware is loaded during the module_init() call. The snd-hda-intel > > > module requests firmware if the patch= parameter is used to load a patch > > > file. This patch works around the problem by deferring the probe in such > > > cases, which will cause the module to load successfully and the driver > > > binding to the device outside the module_init() call. > > > > Is the "recent" change meant 3.6 kernel, or in linux-next? > > > > In anyway, I don't understand why such a change was allowed. Most > > drivers do call request_firmware() at the device probing time. > > If this really has to be resolved in the driver side, it must be a bug > > in the firmware loader core code. > > A good explanation of the problem and subsequent discussion can be found > here: > > http://article.gmane.org/gmane.linux.drivers.video-input-infrastructure/49975 Yeah, but it doesn't justify this ugly module option. It's a simple bug. Papering over it with this option doesn't fix anything. Takashi From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH] ALSA: hda - Defer probe when loading patch firmware Date: Thu, 09 Aug 2012 09:31:30 +0200 Message-ID: References: <1344494723-6827-1-git-send-email-thierry.reding@avionic-design.de> <20120809070813.GA6979@avionic-0098.mockup.avionic-design.de> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 45621265294 for ; Thu, 9 Aug 2012 09:01:47 +0200 (CEST) In-Reply-To: <20120809070813.GA6979@avionic-0098.mockup.avionic-design.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Thierry Reding Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, David Henningsson List-Id: alsa-devel@alsa-project.org At Thu, 9 Aug 2012 09:08:13 +0200, Thierry Reding wrote: > > On Thu, Aug 09, 2012 at 08:57:13AM +0200, Takashi Iwai wrote: > > At Thu, 9 Aug 2012 08:45:23 +0200, > > Thierry Reding wrote: > > > > > > Recent changes to the firmware loading helpers cause drivers to stall > > > when firmware is loaded during the module_init() call. The snd-hda-intel > > > module requests firmware if the patch= parameter is used to load a patch > > > file. This patch works around the problem by deferring the probe in such > > > cases, which will cause the module to load successfully and the driver > > > binding to the device outside the module_init() call. > > > > Is the "recent" change meant 3.6 kernel, or in linux-next? > > > > In anyway, I don't understand why such a change was allowed. Most > > drivers do call request_firmware() at the device probing time. > > If this really has to be resolved in the driver side, it must be a bug > > in the firmware loader core code. > > A good explanation of the problem and subsequent discussion can be found > here: > > http://article.gmane.org/gmane.linux.drivers.video-input-infrastructure/49975 Yeah, but it doesn't justify this ugly module option. It's a simple bug. Papering over it with this option doesn't fix anything. Takashi