Re: [PATCH] ar9170: load firmware asynchronously

[Marcel Holtmann <marcel@holtmann.org>]

Hi Luis,

> > This converts ar9170 to load firmware asynchronously
> > out of ->probe() and only register with mac80211 when
> > all firmware has been loaded successfully. If, on the
> > other hand, any firmware fails to load, it will now
> > unbind from the device.
> >
> > Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
> > ---
> > This can go in now, the prereq patch went in via gregkh.
> >
> > This ought to make it possible to build the driver
> > into the kernel and as long as your system boots
> > within 60 seconds it'll all just work.
> >
> > This is how we need to load firmware for drivers that
> > require the firmware image to detect which features
> > to register to mac80211/cfg80211, but it's also useful
> > when no features depend on the firmware.
> >
> > I've done ar9170 because I'm somewhat familiar with its
> > implementation. b43 should probably be converted to this
> > scheme since it actually has features that depend on the
> > firmware, and libertas_tf has the MAC addresss depending
> > on the firmware (well it needs the firmware to read it).
> >
> > The only complication with this is that now the user is
> > mostly unaware they have a wireless device, they can only
> > find it via lsusb/lspci etc. if firmware loading fails,
> > or from kernel messages. And also manual binding in sysfs,
> > device re-plugging or module re-loading is required to
> > get the module to find the device after putting firmware
> > in place...
> >
> > Still I think this is better than what we have now with
> > many drivers -- if firmware is missing you get network
> > interfaces etc. but cannot ever use them, and it's not
> > always entirely clear that is due to missing firmware.
> 
> Sweet -- we could also expose firmware load events if not done so
> already and let userspace propagate such nasty warnings, I think we'd
> need to pass the firmware expected and the driver the requested it so
> that once the firmware is in place (I guess through inotify maybe) the
> driver modprobe can be retried.

actually PackageKit should be doing something like this already. It
might need to be adapted a bit, but the basics should be there.

Regards

Marcel