Bug#860365: mutter: Graphical glitches on Intel GMA X4500 with SNA and Wayland

[Kevin Keijzer]

Package: mutter
Version: 3.22.3-2
Severity: important

I have a couple of GM45 ThinkPads and G41 desktops running Debian stretch with
the GNOME 3.22 desktop.

Quite regularly, the screen glitches / distorts, followed by this line in
dmesg:

[drm:i965_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun

The easiest way to reproduce this, is by typing text into a GTK application,
such as GNOME Terminal or gedit while running GNOME Shell. This usually
triggers the bug within a minute or two.

In some severe cases, the display would become completely white or grey and
GNOME Shell locks up completely.


Things I've tested that do not make a difference:

- xserver-xorg-video-intel vs built-in modesetting DDX;
- X vs Wayland session;
- Vendor BIOS vs coreboot with different payloads;
- Setting LIBGL_DISABLE_DRI3=1 in /etc/environment.


Things I've tested that do seem to make a difference:

- Using UXA acceleration instead of SNA acceleration.


This, however, can not solve the problem for Wayland of course. But since I've
changed to UXA I haven't seen a single glitch or underrun for over 24 hours
now.


I have tried booting with various drm.debug kernel options, but nothing
interesting is ever shown. Just the FIFO underrun with no additional logging.
There's also nothing in journalctl when a glitch happens.



-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-2-amd64 (SMP w/2 CPU cores)
Locale: LANG=nl_NL.UTF-8, LC_CTYPE=nl_NL.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages mutter depends on:
ii  gsettings-desktop-schemas  3.22.0-1
ii  libc6                      2.24-9
ii  libglib2.0-0               2.50.3-2
ii  libmutter0i                3.22.3-2
ii  libx11-6                   2:1.6.4-3
ii  libxcomposite1             1:0.4.4-2
ii  mutter-common              3.22.3-2
ii  zenity                     3.22.0-1+b1

Versions of packages mutter recommends:
ii  gnome-session [x-session-manager]  3.22.3-1

Versions of packages mutter suggests:
ii  gnome-control-center  1:3.22.2-1
ii  xdg-user-dirs         0.15-2+b1

-- no debconf information