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()

From: Andy Walls <awalls@md.metrocast.net>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Greg KH <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Mauro Carvalho Chehab <mchehab@redhat.com>,
	Ming Lei <ming.lei@canonical.com>, Kay Sievers <kay@vrfy.org>,
	Lennart Poettering <lennart@poettering.net>,
	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>,
	Ivan Kalvachev <ikalvachev@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()
Date: Wed, 03 Oct 2012 18:48:52 -0400	[thread overview]
Message-ID: <3560b86d-e2ad-484d-ab6e-2b9048894a12@email.android.com> (raw)
In-Reply-To: <CA+55aFwjyABgr-nmsDb-184nQF7KfA8+5kbuBNwyQBHs671qQg@mail.gmail.com>

Linus Torvalds <torvalds@linux-foundation.org> wrote:

>On Wed, Oct 3, 2012 at 12:50 PM, Greg KH <gregkh@linuxfoundation.org>
>wrote:
>>>
>>> Ok, like this?
>>
>> This looks good to me.  Having udev do firmware loading and tieing it
>to
>> the driver model may have not been such a good idea so many years
>ago.
>> Doing it this way makes more sense.
>
>Ok, I wish this had been getting more testing in Linux-next or
>something, but I suspect that what I'll do is to commit this patch
>asap, and then commit another patch that turns off udev firmware
>loading entirely for the synchronous firmware loading case.
>
>Why? Just to get more testing, and seeing if there are reports of
>breakage. Maybe some udev out there has a different search path (or
>because udev runs in a different filesystem namespace or whatever), in
>which case running udev as a fallback would otherwise hide the fact
>that he direct kernel firmware loading isn't working.
>
>We can (and will) revert things if that turns out to break things, but
>I'd like to make any failures of the firmware direct-load path be fast
>and hard, so that we can see when/what it breaks.
>
>Ok? Comments?
>
>              Linus
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I don't know if you can remove the /sys/.../firmware ABI altogether, because there is at least one, somewhat popular udev replacement that also uses it: mdev

http://git.busybox.net/busybox/plain/docs/mdev.txt

Regards,
Andy