Issue with mdev and firmware handling

[Denys Vlasenko]

On Thursday 19 March 2009 19:02, Juha Kuikka wrote:
> Using: Busybox 1.12.1
> Problem:
> I am using mdev as the hotplug handler. After handling firmware request from
> my driver mdev removes the corresponding device node in /dev.
> 
> Analysis:
> I whipped up a quick wrapper script to mdev as th hotplug handler and I see
> this:
> 
> ACTION=add
> DEVPATH=/class/firmware/mydev
> FIRMWARE=img.bin
> SUBSYSTEM=firmware
> 
> ACTION=remove
> DEVPATH=/class/firmware/mydev
> FIRMWARE= img.bin
> SUBSYSTEM=firmware
> 
> Kernel sends both add and remove events for the firmware kobject and looking
> at mdev sources it does not seem to differentiate between subsystems so the
> latter message seems to cause the removal of the device node.
> 
> I replaced mdev hotplug handler with a wrapper script at the end of this
> email and it seems to work around the problem.
> 
> What is weird here is that I have used mdev before for firmware handling on
> different systems without this issue so I'm not sure what has changed.
> 
> I'm not sure this kind of fix is the right way to proceed as I'm hardly an
> expert on mdev/udev.

Ok, I added this code to mdev, will see whether this is correct from users'
reports... :(
--
vda