From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755491Ab2HIG5U (ORCPT ); Thu, 9 Aug 2012 02:57:20 -0400 Received: from cantor2.suse.de ([195.135.220.15]:38432 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318Ab2HIG5R (ORCPT ); Thu, 9 Aug 2012 02:57:17 -0400 Date: Thu, 09 Aug 2012 08:57:13 +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: <1344494723-6827-1-git-send-email-thierry.reding@avionic-design.de> References: <1344494723-6827-1-git-send-email-thierry.reding@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 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. thanks, Takashi > > Signed-off-by: Thierry Reding > --- > sound/pci/hda/hda_intel.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index c8aced1..296616e 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -69,6 +69,7 @@ static int probe_only[SNDRV_CARDS]; > static bool single_cmd; > static int enable_msi = -1; > #ifdef CONFIG_SND_HDA_PATCH_LOADER > +static bool deferred[SNDRV_CARDS]; > static char *patch[SNDRV_CARDS]; > #endif > #ifdef CONFIG_SND_HDA_INPUT_BEEP > @@ -3156,6 +3157,16 @@ static int __devinit azx_probe(struct pci_dev *pci, > > if (dev >= SNDRV_CARDS) > return -ENODEV; > + > +#ifdef CONFIG_SND_HDA_PATCH_LOADER > + if (patch[dev] && *patch[dev] && !deferred[dev]) { > + snd_printk(KERN_ERR SFX "deferring probe for patch %s\n", > + patch[dev]); > + deferred[dev] = true; > + return -EPROBE_DEFER; > + } > +#endif > + > if (!enable[dev]) { > dev++; > return -ENOENT; > -- > 1.7.11.4 > 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 08:57:13 +0200 Message-ID: References: <1344494723-6827-1-git-send-email-thierry.reding@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 66731265294 for ; Thu, 9 Aug 2012 08:27:30 +0200 (CEST) In-Reply-To: <1344494723-6827-1-git-send-email-thierry.reding@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 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. thanks, Takashi > > Signed-off-by: Thierry Reding > --- > sound/pci/hda/hda_intel.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index c8aced1..296616e 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -69,6 +69,7 @@ static int probe_only[SNDRV_CARDS]; > static bool single_cmd; > static int enable_msi = -1; > #ifdef CONFIG_SND_HDA_PATCH_LOADER > +static bool deferred[SNDRV_CARDS]; > static char *patch[SNDRV_CARDS]; > #endif > #ifdef CONFIG_SND_HDA_INPUT_BEEP > @@ -3156,6 +3157,16 @@ static int __devinit azx_probe(struct pci_dev *pci, > > if (dev >= SNDRV_CARDS) > return -ENODEV; > + > +#ifdef CONFIG_SND_HDA_PATCH_LOADER > + if (patch[dev] && *patch[dev] && !deferred[dev]) { > + snd_printk(KERN_ERR SFX "deferring probe for patch %s\n", > + patch[dev]); > + deferred[dev] = true; > + return -EPROBE_DEFER; > + } > +#endif > + > if (!enable[dev]) { > dev++; > return -ENOENT; > -- > 1.7.11.4 >