linux-kernel - Re: [PATCH 2/3] firmware: Avoid deadlock of usermodehelper lock at shutdown

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Message-ID: <CACVXFVMRC2L9nBgxTv+20L2gPsRkkkraFTSL19u+KFnunoix6w@mail.gmail.com>
Date:	Wed, 8 May 2013 23:56:51 +0800
From:	Ming Lei <ming.lei@...onical.com>
To:	Takashi Iwai <tiwai@...e.de>
Cc:	linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH 2/3] firmware: Avoid deadlock of usermodehelper lock at shutdown

On Wed, May 8, 2013 at 2:56 PM, Takashi Iwai <tiwai@...e.de> wrote:
> When a system goes to reboot/shutdown, it tries to disable the
> usermode helper via usermodehelper_disable().  This might be blocked
> when a driver tries to load a firmware beforehand and it's stuck by
> some reason.

IMO, it is better to find why the loading is stuck. Also we already provides
the timeout sysfs file to help to deal with the situation.

>
> In this patch, the firmware class driver registers a reboot notifier
> so that it can abort all pending f/w bufs.  Also enable a flag for
> avoiding the call of usermodehelper after the reboot/shutdown starts.

With this patch, maybe we only hide the real problem.

Thanks,
--
Ming Lei
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