linux-kernel - Re: firmware_class warnings on resume

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Message-ID: <56783CE4.8080405@redhat.com>
Date:	Mon, 21 Dec 2015 09:54:44 -0800
From:	Laura Abbott <labbott@...hat.com>
To:	Andy Lutomirski <luto@...capital.net>,
	Ming Lei <ming.lei@...onical.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: firmware_class warnings on resume

On 12/20/2015 04:20 AM, Andy Lutomirski wrote:
> I hit this warning fairly frequently when resuming 4.4-rc5:
>
>          ret = usermodehelper_read_trylock();
>          if (WARN_ON(ret)) {
>              dev_err(device, "firmware: %s will not be loaded\n",
>                  name);
>              goto out;
>          }
>
> It seems like it could be improved in two ways fairly easily:
>
> 1. Shouldn't firmware_class try the direct load before trying to get
> the usermodehelper lock?
>
> 2. Why is the !NOWAIT case doing a trylock?  That seems wrong.
>
> --Andy
>

  
I saw the same warning coming from the bluetooth stack, see the thread
http://article.gmane.org/gmane.linux.kernel/1950940 and
http://article.gmane.org/gmane.linux.kernel/1940130.
At least in the bluetooth case, the conclusion was the firmware request
should not be happening at that point in time and the reset_resume function
should be implemented instead. I put that work aside and haven't picked
it up again.

Thanks,
Laura
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