Dear Maintainer,

I reported this to mesa-libgallium since the segfault comes from
libgallium-25.0.0-1.so, but the issue might actually come from elsewhere in
mesa, I don't know how to pinpoint it further.

After upgrading from mesa-libgallium=24.3.4-3, gdm fails to start on
wayland.
It instead fall back to an Xorg session, which has very high CPU usage
for some
reason (Xorg is using ~70% CPU at idle, and whenever I play a video I
get 100%
CPU usage for Xorg and stutters). I have the following error in my
journalctl
when I activate gdm3 debug mode :

mars 02 21:01:07 pakuh org.gnome.Shell.desktop[2931]: libEGL warning: egl:
failed to create dri2 screen
mars 02 21:01:07 pakuh org.gnome.Shell.desktop[2931]: libEGL warning: egl:
failed to create dri2 screen
mars 02 21:01:07 pakuh kernel: gnome-shell[2931]: segfault at 8 ip
00007f4055508a3d sp 00007ffd48aef490 error 4 in
libgallium-25.0.0-1.so[108a3d,7f40554e1000+1735000] likely on CPU 12
(core 4,
socket 0)
mars 02 21:01:07 pakuh kernel: Code: fa 41 55 41 54 55 89 f5 53 48 89 fb
48 83
ec 08 4c 8b 67 58 0f b6 05 d3 4d 78 02 84 c0 0f 84 9a 00 00 00 0f b6 05
c3 4d
78 02 <41> 83 7c 24 08 03 4c 8d 2d 56 0c 66 02 88 83 68 01 00 00 7e 0f 49
mars 02 21:01:07 pakuh /usr/libexec/gdm-wayland-session[2897]:
gnome-session-
binary[2897]: DEBUG(+): GsmAutostartApp: (pid:2931) done (signal:11)

Downgrading mesa-libgallium and its dependencies to 24.3.4-3 fixes the
issues,
and I can get a wayland session working again, with no lag. The downgrade I
made is the following :

Downgrade: libgles2-mesa-dev:amd64 (25.0.0-1, 24.3.4-3), libglx-mesa0:amd64
(25.0.0-1, 24.3.4-3), libglx-mesa0:i386 (25.0.0-1, 24.3.4-3), libgbm1:amd64
(25.0.0-1, 24.3.4-3), libgbm1:i386 (25.0.0-1, 24.3.4-3),
mesa-libgallium:amd64
(25.0.0-1, 24.3.4-3), mesa-libgallium:i386 (25.0.0-1, 24.3.4-3),
libxatracker2:amd64 (25.0.0-1, 24.3.4-3), mesa-va-drivers:amd64 (25.0.0-1,
24.3.4-3), mesa-va-drivers:i386 (25.0.0-1, 24.3.4-3), libgl1-mesa-dri:amd64
(25.0.0-1, 24.3.4-3), libgl1-mesa-dri:i386 (25.0.0-1, 24.3.4-3),
libosmesa6:amd64 (25.0.0-1, 24.3.4-3), mesa-vulkan-drivers:amd64 (25.0.0-1,
24.3.4-3), mesa-vulkan-drivers:i386 (25.0.0-1, 24.3.4-3), libegl-mesa0:amd64
(25.0.0-1, 24.3.4-3), libegl-mesa0:i386 (25.0.0-1, 24.3.4-3), mesa-vdpau-
drivers:amd64 (25.0.0-1, 24.3.4-3)

I have 2 GPU on my system : an AMD R7 240, using the radeon driver,
which I'm
using, and a GTX 1080 Ti which is bound to vfio-pci (for
vfio-passthrough), and
is completely unavailable to gdm : I've checked at boot, and it doesn't
appear
in /dev/dri - only the AMD card is here.

AMD Cape Verde GL [FirePro W4100].

Downgrading mesa packages to 24.3.4-3 fixes the problem.

I don't see an upstream issue which matches this on
gitlab.freedesktop.org/mesa.

The problem disappeared on my AMD Cape Verde GL [FirePro W4100] after
upgrading straight to 25.0.2.

Unfortunately I still have this issue with version 25.0.3-1 of
Mesa. No Wayland session can start because of the segfault in
libgallium.

I keep pretty up-to-date with unstable. From my logs, it looks like
I booted on April 4 into Wayland just fine, and then my next boot
was on April 12 and I saw the error then and on every boot since.

bg