Re: in-kernel drivers and firmware loader

From: Johannes Berg
Date: Fri May 11 2012 - 07:09:19 EST


On Fri, 2012-05-11 at 13:03 +0200, Kay Sievers wrote:

> > I am testing on a PandaBoard which boots a linux kernel without a initrd
> > and our device is detected before the root filesystem is mounted. I was
> > expecting the async firmware request to get called back immediatly with
> > firmware pointer being NULL. The behaviour is slightly different as this
> > callback is coming after 60 seconds, which is the timeout. I guess the
> > uevent just gets lost without the kernel knowing it. Is that correct?
>
> It's probably sent, but nothing see it because there is no userspace
> that would have subscribed.
>
> If udev is started later during bootup, and the coldplug triggers all
> events again, the firmware request should be found and be fulfilled by
> userspace -- at least that's the theory.

I haven't really read all of the message, but we've also had users who
observed in some cases that the coldplug doesn't properly trigger
firmware load requests. Unfortunately, I don't have any details.

johannes

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