Subject: Re: firmware_class warnings on resume
To: Andy Lutomirski <luto@amacapital.net>, Ming Lei <ming.lei@canonical.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <CALCETrUKf9krSdZ19wQ4gzWr4y3BB6Aey9j8LOd3eg-F8nVwxA@mail.gmail.com>
From: Laura Abbott <labbott@redhat.com>
Message-ID: <56783CE4.8080405@redhat.com>
Date: Mon, 21 Dec 2015 09:54:44 -0800
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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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