Re: Who mounts sysfs?

[Greg KH <greg@kroah.com>]

On Thu, Jun 25, 2009 at 11:36:29AM +0100, Will Newton wrote:
> Hi all,
> 
> I'm trying to get the libertas driver working on an embedded
> development board and I've run into what looks like a sysfs problem.
> Although I'm actually using the BusyBox mdev hotplug helper rather
> than udev, I hope this is the right list to be asking this question.

For busybox questions, not really, but we reserve the right to poke fun
at you for using mdev :)

> What appears to be happening is I get my initramfs extracted, so I
> have access to the various necessary files including the hotplug
> helper and my firmware files. This step is taken care of by the rootfs
> initcall level. Then the driver initcalls are run, including the
> libertas setup routines, which call request_firmware. request_firmware
> fires off a uevent and calls the hotplug helper. The hotplug helper
> looks for the /sys/class/firmware entry for the libertas device, but
> it doesn't find one because I don't appear to have a mounted sysfs on
> the /sys mountpoint.
> 
> So my question is: who should be mounting sysfs here? init will mount
> sysfs, but is run much later than the device initcalls.

You need to mount sysfs as one of the first things to have happen.  Look
at your distro's startup scripts as an example of this.

good luck,

greg k-h