Re: udev breakages - was: Re: Need of an ".async_probe()" type ofcallback at driver's core - Was: Re: [PATCH] [media] drxk: change it to use request_firmware_nowait()
From: Linus Torvalds
Date: Tue Oct 02 2012 - 12:33:18 EST
On Tue, Oct 2, 2012 at 6:03 AM, Mauro Carvalho Chehab
> I basically tried a few different approaches, including deferred probe(),
> as you suggested, and request_firmware_async(), as Kay suggested.
Stop this crazy. FIX UDEV ALREADY, DAMMIT.
Who maintains udev these days? Is it Lennart/Kai, as part of systemd?
Lennart/Kai, fix the udev regression already. Lennart was the one who
brought up kernel ABI regressions at some conference, and if you now
you have the *gall* to break udev in an incompatible manner that
requires basically impossible kernel changes for the kernel to "fix"
the udev interface, I don't know what to say.
"Two-faced lying weasel" would be the most polite thing I could say.
But it almost certainly will involve a lot of cursing.
> However, for 3.7 or 3.8, I think that the better is to revert changeset 177bc7dade38b5
> and to stop with udev's insanity of requiring asynchronous firmware load during
> device driver initialization. If udev's developers are not willing to do that,
> we'll likely need to add something at the drivers core to trick udev for it to
> think that the modules got probed before the probe actually happens.
The fact is, udev made new - and insane - rules that are simply
*invalid*. Modern udev is broken, and needs to be fixed.
I don't know where the problem started in udev, but the report I saw
was that udev175 was fine, and udev182 was broken, and would deadlock
if module_init() did a request_firmware(). That kind of nested
behavior is absolutely *required* to work, in order to not cause
idiotic problems for the kernel for no good reason.
What kind of insane udev maintainership do we have? And can we fix it?
Greg, I think you need to step up here too. You were the one who let
udev go. If the new maintainers are causing problems, they need to be
fixed some way.
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