Question about mouse grabbing and X on Apple hardware.

[Super Bisquit]

On Wed, Aug 3, 2011 at 4:13 AM, Matthieu Herrb <matthieu.herrb at laas.fr>wrote:

> On Wed, Aug 03, 2011 at 03:18:22AM -0400, Super Bisquit wrote:
> > On Wed, Aug 3, 2011 at 1:49 AM, Matthieu Herrb <matthieu.herrb at laas.fr
> >wrote:
> >
> > > On Tue, Aug 02, 2011 at 07:00:12PM -0400, Super Bisquit wrote:
> > > > My apologies before hand.
> > > > I'm wondering how the OpenBSD PPC port dealt with the mouse
> > > > grabbing.
> > >
> > > Sorry, I don't understand the question. What kind of grabbing are you
> > > talking about? At the X server level, there is nothing MI in this
> > > area.
> > >
> >
> > The mouse pointer will get caught on the left edge of the screen and then
> > only a restart of X allows the pointer to be free again.
> > And thanks for the reply.
>
> On OpenBSD/macppc, I don't remember having seen that problem, but I
> may be wrong, and I don't use it on a daily basis anymore. We had it
> on other architectures though.
>
> The main reason for this bug is the SIGIO handler in the
> Xserver. By default X processes all the data from the mouse driver in
> the signal handler attached to SIGIO. With the new pointer
> acceleration code this includes a good amount of floating point
> computations, and may even trigger some MMX/SSE2 operations in
> libpixman to repaint the pointer on the screen.
>
> If your signal handling code doesn't preserve the FPU (and the
> altivec) registers, this is likely to trigger the bug.
>
> The easiest solution is to disable the code that uses SIGIO to
> asynchronously update the pointer. pass --disable-use-sigio-by-default
> to configure for this, or set the option in xorg.conf.
>
> >
> >
> > >
> > > > I would like- if possible and with permission- to use the same method
> > > with
> > > > FreeBSD PowerPC to solve/prevent the grabbing.
> > > > Again, my apologies beforehand if this post to the mailing list seems
> or
> > > is
> > > > out of place.
>
>
> --
> Matthieu Herrb
>

Thank you for the help and tell DeRaadt thanks also. I'm forwarding this
mail to the FreeBSD PowerPC list for the others to see it.