linux-kernel - Re: [PATCH] ALSA: hda - Defer probe when loading patch firmware

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <s5hd330frn1.wl%tiwai@suse.de>
Date:	Thu, 09 Aug 2012 09:31:30 +0200
From:	Takashi Iwai <tiwai@...e.de>
To:	Thierry Reding <thierry.reding@...onic-design.de>
Cc:	Jaroslav Kysela <perex@...ex.cz>,
	David Henningsson <david.henningsson@...onical.com>,
	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ALSA: hda - Defer probe when loading patch firmware

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/