Re: 2.6.30-rc6: Reported regressions from 2.6.29

Kay Sievers
2009-05-17T00:15:52Z

On Sun, May 17, 2009 at 02:01, Linus Torvalds
<torvalds@linux-foundation.org> wrote:

>        [   10.428691] Error: Driver 'rtc_cmos' is already registered, aborting...
>
> but the driver doesn't really care whether that succeeded or not, but then
> the platform_driver_probe fails (because the thing is already in use), so
> then it ends up unregistering something that never got registered in the
> first place.
>
> I think this is strictly speaking a bug in driver_unregister(), which is
> too fragile. If you unregister a drivert that wasn't registered, we
> shouldn't oops.
>
> But we could certainly do it at the rtc-cmos.c level too, and just not
> unregister it if the registration failed. My gut feel is that we should
> aim for the core driver helpers to be less fragile, though - we'll always
> have driver bugs.

In:
driver_remove_file()
we try to access the private part:
sysfs_remove_file(&drv->p->kobj, ...
and that is NULL, for an unregistered driver, I would expect.

I'm looking into it.

Kay