[Mageia-dev] Problem with gdm metacity again

Wed Sep 7 19:18:30 CEST 2011

On Wed, 07 Sep 2011 13:27:05 +0100
+Colin Guthrie <mageia at colin.guthr.ie> wrote:
+
+> 'Twas brillig, and JA Magallon at 07/09/11 12:03 did gyre and gimble:
+> > On Wed, 7 Sep 2011 13:01:39 +0300
+> > Shlomi Fish <shlomif at shlomifish.org> wrote:
+> > 
+> >> Hi J. A.,
+> >>
+> >> On Wed, 7 Sep 2011 11:42:33 +0200
+> >> JA Magallon <jamagallon at ono.com> wrote:
+> >>
+> >>> On Wed, 7 Sep 2011 11:15:21 +0200
+> >>> JA Magallon <jamagallon at ono.com> wrote:
+> >>>
+> >>>> Hi...
+> >>>>
+> >>>> This old problem has surfaced again:
+> >>>>
+> >>>> .xsession-errors:
+> >>>>
+> >>>> ...
+> >>>> Window manager warning: Screen 0 on display ":0" already has a window manager; try using the --replace option to replace the current window manager.
+> >>>> Window manager warning: Screen 0 on display ":0" already has a window manager; try using the --replace option to replace the current window manager.
+> >>>> ...
+> >>>>
+> >>>> I get only the nautilus desktop, with two black bars on top and bottom of the screen.
+> >>>> If I launch a terminal, 'gnome-shell --replace' works fine.
+> >>>>
+> >>
+> >> I reported this bug here:
+> >>
+> >> https://bugs.mageia.org/show_bug.cgi?id=2628
+> >>
+> >> I can reproduce it here on my x86-64 Mageia Linux Cauldron laptop.
+> >>
+> >> Regards,
+> >>
+> >> 	Shlomi Fish
+> >>
+> >>>> Any idea ?
+> >>>> Can it be some personal setting ?
+> >>>>
+> >>>> TIA
+> >>>
+> >>> Digging a bit more, something is wrong detecting acceleration.
+> >>> In GDM log:
+> >>>
+> >>> gnome-session[4752]: DEBUG(+): fill: *** Looking if /usr/share/gnome-session/sessions/gdm-shell.session is a valid session file
+> >>> gnome-session[4752]: DEBUG(+): fill: *** Launching helper 'bash -c "gnome-shell --help | grep -q gdm-mode && /usr/lib64/gnome-session-check-accelerated"' to know if session is runnable
+> >>> gnome-session-is-accelerated: No hardware 3D support.
+> >>> gnome-session-check-accelerated: Helper exited with code 256
+> >>> gnome-session[4752]: WARNING: Session 'gdm-shell' runnable check failed: Exited with code 1
+> >>> gnome-session[4752]: DEBUG(+): fill: *** Session is not runnable
+> >>> gnome-session[4752]: DEBUG(+): fill: *** Getting session 'gdm-fallback'
+> >>>
+> >>> This is for GDM's own session.
+> >>> The same happens for user.
+> >>>
+> >>> Any ideas ? How can I check why this fails ?
+> >>> Its a netbook with Intel graphics, so it uses Mesa.
+> >>>
+> >>> Will check on an nvidia system too.
+> >>>
+> > 
+> > I did, and everything works fine. I even discovered that GDM looks different
+> > when acceleration is available ;)).
+> > 
+> > So these are two separate problems:
+> > 
+> > - Acceleration detection on some systems, from my limited tests, it works on
+> >   nVidia (32bit, will check 64 shortly), and fails on intel (mesa???) graphics.
+> >   This can be a bug report for gnome-session (/usr/lib64/gnome-session-check-accelerated*)
+> >   or for Mesa if it's it what breaks things.
+> > 
+> > - In full mode, gnome-shell from the user replaces gnome-shell from gdm.
+> >   But in fallback mode, gnome-shell can't replace GDM's metacity.
+> 
+> It's almost certainly a permissions thing.
+> 
+
+Yup, thats the problem.
+Booting into systemd gives this:
+
+one:~# ll /dev/dri*
+total 0
+crw-rw----+ 1 root video 226,  0 2011.09.07 15:12 card0
+crw-rw-rw-  1 root video 226, 64 2011.09.07 15:12 controlD64
+one:~# getfacl /dev/dri/card0
+getfacl: Removing leading '/' from absolute path names
+# file: dev/dri/card0
+# owner: root
+# group: video
+user::rw-
+user:gdm:rw-
+group::rw-
+mask::rw-
+other::---
+
+But with init, card0 has no acl.
+
+As a quick hack,
+
+one:/dev/dri# service dm stop
+Stopping display manager:                                       [  OK  ]
+one:/dev/dri# chmod 666 card0
+one:/dev/dri# ll
+total 0
+crw-rw-rw- 1 root video 226,  0 2011.09.07 19:15 card0
+crw-rw-rw- 1 root video 226, 64 2011.09.07 19:15 controlD64
+one:/dev/dri# service dm start
+Starting display manager:                                       [  OK  ]
+one:/dev/dri#
+
+made it work!
+
+> I'm not sure GDM registers itself with consolekit anymore. And
+> in-so-doing, will not get permissions on the DRI device and thus will
+> not be able to run the nice new shell.
+> 
+> 
+> If you run systemd then all should be well.
+> 
+> Col
+> 
+> 
+> 
+
+