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Bug 771186 - Gnome 3.21.90 (Debian stretch/sid) unable to control display
Gnome 3.21.90 (Debian stretch/sid) unable to control display
Status: RESOLVED INVALID
Product: gnome-shell
Classification: Core
Component: general
3.20.x
Other Linux
: Normal critical
: ---
Assigned To: mutter-maint
mutter-maint
Depends on:
Blocks:
 
 
Reported: 2016-09-10 13:51 UTC by Petr Pulc
Modified: 2016-09-10 17:30 UTC
See Also:
GNOME target: ---
GNOME version: ---


Description Petr Pulc 2016-09-10 13:51:39 UTC 
After last update, brightness Fn key stops working and gnome-control-center shows "Could not get screen information" in Displays section.

xrandr is able to detect screen without problem:
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
   1366x768      60.01*+  39.97
...

lspci correctly detects GPU:
00:02.0 VGA compatible controller: Intel Corporation Sky Lake Integrated Graphics (rev 07)

laptop-mode enabled, no brightness config in there, no change since last update

no vendor control in grub
Comment 1 Petr Pulc 2016-09-10 16:08:02 UTC 
Gnome shell / Mutter version is 3.20.3
Comment 2 André Klapper 2016-09-10 16:47:27 UTC 
This bug report states "Gnome 3.21.90" but also "gnome-shell 3.20.3". Can you clarify? Which parts of your setup are stable 3.20, which parts are unstable 3.21, and why do you mix them?
Comment 3 Petr Pulc 2016-09-10 16:55:54 UTC 
(In reply to André Klapper from comment #2)

That is more of a question to the Debian guys... Yet I don't see a reason why for example the backlight control should not work.

Versions of involved packages:

gnome-control-center 3.21.90-1
gnome-shell 3.20.3-1+b1

In Details section, version 3.21.90 is shown...
Comment 4 Florian Müllner 2016-09-10 17:17:53 UTC 
The brightness Fn keys are handled between gnome-settings-daemon and gnome-shell via a private DBus API. Display configuration is handled between gnome-control-center and mutter, again via a private DBus API. Those APIs must not break within a stable version, but when you start mixing core components, all bets are off.

Unless you can reproduce with all those components at 3.20.x or all at 3.21.9x, there's no bug from our point of view, sorry.
Comment 5 Petr Pulc 2016-09-10 17:30:07 UTC 
Understood, treating as a bug from Debian, thanks for pointing to the right packages.