On Thu, Jun 25, 2009 at 5:28 PM, Greg KH<greg@xxxxxxxxx> wrote: > On Thu, Jun 25, 2009 at 04:53:07PM +0100, Will Newton wrote: >> On Thu, Jun 25, 2009 at 4:18 PM, Greg KH<greg@xxxxxxxxx> wrote: >> > 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. >> >> Yes, I want my sysfs mounted as early as possible, but userspace (via >> /sbin/init) does not get a chance to do this until after the device >> initcalls have been run. I'm interested to know if there's a standard >> way to get sysfs mounted before /sbin/init is run. > > There isn't. Ok, so we cannot expect sysfs to be mounted on /sys before /sbin/init has been run? What do we do with callers of request_firmware prior to /sbin/init running? Should drivers that require firmware always be modules? I would rather build in my drivers monolithically if possible for ease of deployment and boot speed. Is there some non-standard other way of mounting sysfs people are using in this situation? >> I could modify mdev to mount sysfs if it detects that it isn't >> already, but that seems like something of a hack. > > Yeah, that sounds wrong. Look at how your desktop distro does this, > this shouldn't be an issue. Looks like RHEL calls mount in /etc/rc.sysinit, which is still a bit late for drivers calling request_firmware that are built in to the kernel. -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
