Re: [PATCH 0/2] Provide a driver for the Apple Magic Mouse - opps

Dmitry Torokhov
2010-02-15T07:11:55Z

On Sun, Feb 14, 2010 at 09:22:41AM -0500, Ed Tomlinson wrote:
> On Sunday 14 February 2010 03:03:44 Dmitry Torokhov wrote:
> > On Sat, Feb 13, 2010 at 02:29:29PM -0500, Ed Tomlinson wrote:
> > > On Wednesday 10 February 2010 08:57:37 Jiri Kosina wrote:
> > > > On Tue, 9 Feb 2010, Michael Poole wrote:
> > > >
> > > > > I think this patch is ready for real review. The Magic Mouse requires
> > > > > that a driver send an unlock Report(Feature) command, similar to the
> > > > > Wacom wireless tablet and Sixaxis controller quirks. This turns on an
> > > > > Input Report that isn't published in the input Report descriptor that
> > > > > contains touch data (and usually overrides the normal motion and click
> > > > > Report).
> > > > >
> > > > > Because the mouse has only one switch and no scroll wheel, the driver
> > > > > (under control of parameters) emulates a middle button and scroll wheel.
> > > > > User space could also ignore and/or re-synthesize those events based on
> > > > > the reported events.
> > > > >
> > > > > The first patch exports hid_register_report() so the driver can turn on
> > > > > the multitouch report. The second patch adds the device ID and the
> > > > > driver. Some user-space tools to talk to the mouse directly (that is,
> > > > > when it is not associated with the host's HIDP stack) are at
> > > > > http://github.com/entrope/linux-magicmouse .
> > > >
> > > > I have applied the driver into apple_magic_mouse branch and merged this
> > > > branch into for-next, so it should appear in the upcoming linux-next.
> > >
> >
> > > This driver (or the hid changes) can triggers an opps. What I did was
> > > start X. Turn on the magic mouse. It connected on input7&8. Then I
> > > powered it off and on. This time it conneced on input9&10. Then I
> > > exited X and got the opps. Note my X does not hotplug the magic
> > > mouse. I've also included a trace of the udev events that generated
> > > the log below (if there was a remove after X stopped it would not be
> > > included). To my eyes it looks like we leak an input device (there is
> > > not a remove event for input8).
> > >
> >
> > Indeed, we seem to be missing call to input_unregister_device() in
> > magicmouse_remove().
>
> How does this look? With this udevadm shows input8 being removed and
> there is no more opps.

Almost... you need to do hid_hw_stop() first and only then unregister
input device, Otherwise if you unload the module while moving the mouse
it is likely to still oops.

Thanks.

--
Dmitry