Bug#795390: mutter: Please backport the fix for upstream bug 728464 to Jessie

[Mert Dirik]

Package: mutter
Version: 3.14.4-1~deb8u1.2
Severity: wishlist
Tags: upstream patch

Dear maintainers,

Problem:

There are some screen update problems regarding the interaction
between various compositing window managers and the binary NVIDIA
driver.  mutter is not an exception to that.

It has not been reported to Debian mutter/gnome-shell packages but it
is indeed a common and a very annoying problem, and Debian reporters
seem to gather around the nvidia-driver bug #755683.

I will not talk about the problem much. A summary I wrote a few days
ago can be seen at [3]. Upstream bug report can be seen at
[1]. Relevant Debian bug report on the nvidia-driver package can be
seen at [2].

Fix:

The proper fix requires a cooperation between the driver and
compositor, namely adding support for "GL_EXT_x11_sync_object"
interface. NVIDIA driver provides that feature for quite some time
(since 2011 I guess). A patch for compositors has been written by an
NVIDIA developer and it is shipping with other compositors such as
compton and compiz. It is actually the same patch that has been
applied to mutter last week.

While adding a new feature like that seem like an invasive change, the
patch is actually not invasive at all. It consists of mostly additions
and changes only small number of lines.  There are 4 upstream commits
right now, namely 39763d, 9df6cd, b0b08d and 299ed4 on master
branch. Upstream developer also backported them to the 3.14 branch
recently [4].

My opinion:

I have been using a patched version of 3.14.4-1~deb8u1 for almost a
week now and it is working really well.  I have been using 39763d and
9df6cd for 6 days and b0b08d for 4 days. I have not tried 299ed4 yet
(since it's few hours old).

I'm on NVIDIA driver 340.76. Note that it's slightly newer than the
one in Jessie (340.65), so you may want to be sure there is not a
problem with old version (even though the driver support for that
feature is much older than the patch itself).

As you can see, the fix is new and still being refined; so you may
 want to wait until it is shipped in a stable release before
 backporting it to Jessie. On the other hand, same patch is already
 shipped in compiz and compton, and it has even been backported to LTS
 version of Compiz earlier this year, so it's not wrong to think that
 it's a relatively safe patch.

Thanks for your time!

[1] https://bugzilla.gnome.org/show_bug.cgi?id=728464

[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=755683

[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=755683#62

[4] https://bugzilla.gnome.org/show_bug.cgi?id=728464#c116



-- System Information:
Debian Release: 8.1
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'proposed-updates'), (500,
'stable')
Architecture: i386 (x86_64)
Foreign Architectures: amd64

Kernel: Linux 3.16.0-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages mutter depends on:
ii  gnome-themes-standard      3.14.2.2-1
ii  gsettings-desktop-schemas  3.14.1-1
ii  libc6                      2.19-18
ii  libclutter-1.0-0           1.20.0-1
ii  libglib2.0-0               2.42.1-1
ii  libmutter0e                3.14.4-1~deb8u1.2
ii  libx11-6                   2:1.6.2-3
ii  libxcomposite1             1:0.4.4-1
ii  mutter-common              3.14.4-1~deb8u1.2
ii  zenity                     3.14.0-1

Versions of packages mutter recommends:
ii  gnome-session [x-session-manager]  3.14.0-2
ii  openbox [x-session-manager]        3.5.2-8

Versions of packages mutter suggests:
ii  gnome-control-center  1:3.14.2-3
ii  xdg-user-dirs         0.15-2