Re: linux-next: dock_link_device is oopsy

[Holger Macht <holger@homac.de>]

On Sa 18. Feb - 13:03:34, Hugh Dickins wrote:
> On Sat, 18 Feb 2012, Holger Macht wrote:
> > On Sa 18. Feb - 10:46:04, Hugh Dickins wrote:
> > > On Sat, 18 Feb 2012, Holger Macht wrote:
> > > > How about that one?
> > > 
> > > It's more broken than that.  Here's my attempt.  It boots on the
> > > systems with dock_station_count 0, and it boots on my laptop with
> > > dock_station_count 2; but I don't actually have any docking station,
> > > so it still doesn't test very much (dock is 0 after the loop).
> > 
> > Well, there doesn't have to actually exist a physical dock station (or
> > bay device) for dock_station_count to be > 0. It just tells that the
> > ACPI objects are present and thus the system is capable of it.
> > 
> > So does this function actually also break on your laptop and you're
> > getting the oops there, too?
> 
> It oopsed on the 4-year-old Fujitsu-Siemens laptop whose dock_station_count
> was 0.  It did not oops on the new ThinkPad laptop whose dock_station_count
> is 2, but no docks were found: so the function would only have been leaking
> memory on that.

It should actually have successfully linked the dock to the device, if
for instance you had a device in your bay. At least this is working fine
with two Thinkpads I tested with. That's why I didn't encounter this
problem at all before resubmitting the corresponding patch set.

> If docks were found, then I suspect it could have been scribbling, but I
> cannot actually check if that's true (for all I know, dock_station_count
> may be always 1 bigger than the most that that double loop can discover);
> but at least the loop is now made safe against scribbling.

It was actually working fine multiple times, out of pure luck it seems.

Regards,
 Holger