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From: Lucas De Marchi <lucas.de.marchi@gmail.com>
Date: Wed, 3 Oct 2012 19:15:31 -0300
Message-ID: <CAKi4VALw4ZACPwA6kTpRiDHtHBoYtpZm_T_iJZdF4etDoUJTkQ@mail.gmail.com>
Subject: Re: udev breakages - was: Re: Need of an ".async_probe()" type of
 callback at driver's core - Was: Re: [PATCH] [media] drxk: change it to use request_firmware_nowait()
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ivan Kalvachev <ikalvachev@gmail.com>,
        Mauro Carvalho Chehab <mchehab@redhat.com>,
        Lennart Poettering <lennart@poettering.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Kay Sievers <kay@redhat.com>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        Michael Krufky <mkrufky@linuxtv.org>
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On Tue, Oct 2, 2012 at 7:37 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Tue, Oct 2, 2012 at 2:03 PM, Ivan Kalvachev <ikalvachev@gmail.com> wrote:
>>
>> I'm not kernel developer and probably my opinion would be a little
>> naive, but here it is.
>>
>> Please, make the kernel load firmware from the filesystem on its own.
>
> We probably should do that, not just for firmware, but for modules
> too. It would also simplify the whole "built-in firmware" thing
>
> Afaik, the only thing udev really does is to lok in
> /lib/firmware/updates and /lib/firmware for the file, load it, and
> pass it back to the kernel. We could make the kernel try to do it
> manually first, and only fall back to udev if that fails.
>
> Afaik, nobody ever does anything else anyway.
>
> I'd prefer to not have to do that, but if the udev code is buggy or
> the maintainership is flaky, I guess we don't really have much choice.
>
> Doing the same thing for module loading is probably a good idea too.

humn... I don't think so. It would work perfectly well for firmware,
but for modules there are more things involved like fulfilling
dependencies, soft-dependencies, aliases and the like. It would create
several regressions.

> There were already people (from the google/Android camp) who wanted to
> do module loading based on filename rather than the buffer passed to
> it, because they have a "I trust this filesystem" model.

They wanted to pass a fd instead of a buffer. That is being done in
the new finit_module syscall being discussed:
http://www.gossamer-threads.com/lists/linux/kernel/1592271?do=post_view_flat


Lucas De Marchi