[PATCH] libertas: fix error handling

[Holger Schurig]

> > -	unregister_netdev(dev);
> > +		if (dev && dev->reg_state)
> > +			unregister_netdev(dev);

> This is a layering violation... Shouldnt poke into
> dev->reg_state from driver context like this.

I agree. However, if the release function is called twice, then 
unregister_netdev() complains. And I saw nothing like 
is_netdev_registered() (or similar) in 
include/linux/netdevice.h.

> Undoing initialization steps (error handling) should be done
> at the initialization sites. Having a single function for both
> half-initialized and full removal/unregister cases is
> confusing and bug-prone.

I agree.

> Can you please cook a patch to handle failures at
> initialization instead of this?


Let's explain the reason why I coded it the way it is:

The problem is that currently our card can be un-unitialized. I 
had to break wlan_add_card() into an add-card, set-hw-funcs and 
start-card functionality, because two of them are 
hardware-independ and one is not.

Now, the add-card functionality requests memory. If that wouldn't 
work, it could tear down that inside itself. That is common 
practice.

The set-hw-funcs cannot have an error, no problem here.

But the start-card functionality CAN produce errors. And it can 
clean up it's own mess .....  but it cannot call back into the 
add-card function to clean up the mess there.

Therefore I thought about about a common clean-up routine that 
can tidy up everything, no matter what.