[PATCH] xfree86: Keep a non-seat0 X server from touching VTs (#71258)

[Laércio de Sousa]

Hi David,

I'm currently using this patch with a dual-seat system consisting of a
primary Intel onboard video chip and a secondary Silicon Motion SM501
graphics card with no DRM/KMS drivers available (much like a NVIDIA card
with proprietary drivers). At the moment, I've observed no problems at all,
but more tests will be really welcome.

CANTATE DOMINO CANTICUM NOVUM
QUIA MIRABILIA FECIT

Laércio


2013/11/11 David Herrmann <dh.herrmann at gmail.com>

> Hi
>
> On Thu, Nov 7, 2013 at 5:53 PM, Laércio de Sousa <lbsousajr at gmail.com>
> wrote:
> > This is my first atempt to block VT access to non-seat0 X servers.
> >
> > If -seat option is passed with a value different from seat0,
> > X server won't call xf86OpenConsole().
> >
> > This is needed to avoid any race condition between seat0 and
> > non-seat0 X servers. If a non-seat0 X server opens a given VT
> > before a seat0 one which expects to open the same VT, one can
> > get an inactive systemd-logind graphical session for seat0.
> >
> > This patch was first tested in a multiseat setup with multiple
> > video cards and works quite well.
> >
> > I suppose it can also make things like DontVTSwitch and -sharevts
> > meaningless for non-seat0 seats, so it may fix bug #69477, too.
> >
> > Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=71258
> >        https://bugs.freedesktop.org/show_bug.cgi?id=69477 (maybe)
> >
> > See also:
> http://lists.x.org/archives/xorg-devel/2013-October/038391.html
> >           https://bugzilla.redhat.com/show_bug.cgi?id=1018196
> > ---
> >  hw/xfree86/common/xf86Init.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c
> > index 91ec4c8..a678f4d 100644
> > --- a/hw/xfree86/common/xf86Init.c
> > +++ b/hw/xfree86/common/xf86Init.c
> > @@ -545,7 +545,7 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char
> **argv)
> >                  want_hw_access = TRUE;
> >
> >              if (!(flags & HW_SKIP_CONSOLE))
> > -                xorgHWOpenConsole = TRUE;
> > +                xorgHWOpenConsole = !ServerIsNotSeat0();
>
> Did you test that? I don' know whether there are any implications if
> we don't open the VT. The idea sounds good, though. I'd like to see
> that applied upstream. However, maybe someone can comment why
> "sharedvt" was introduced in the first place?
>
> Thanks
> David
>
> >          }
> >
> >          if (xorgHWOpenConsole)
> > --
> > 1.8.1.4
> >
> > _______________________________________________
> > xorg-devel at lists.x.org: X.Org development
> > Archives: http://lists.x.org/archives/xorg-devel
> > Info: http://lists.x.org/mailman/listinfo/xorg-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.x.org/archives/xorg-devel/attachments/20131111/3a679a05/attachment.html>