F25 Self Contained Change: Better Switchable Graphics Support

[Jan Kurik]

= Proposed Self Contained Change: Better Switchable Graphics Support =
https://fedoraproject.org/wiki/Changes/BetterSwitchableGraphicsSupport

Change owner(s):
* Hans de Goede <hdegoede AT redhat DOT com>

All modern laptops have a gpu integrated into their processor (the
igpu), some models also have a more powerful dedicated gpu (dgpu),
this is called switchable graphics. The goal of this feature is to
improve Fedora's support for such laptops.


== Detailed Description ==
By default all apps will run on the more energy efficient igpu and the
OS can choose to switch to the dgpu when more gpu-power is necessary,
trading battery time for graphics performance. On most laptops the
default gpu can be changed to the dgpu so that everything will always
run on the dgpu.

Linux support for switchable graphics currently is not very good. E.g.
on many laptops some of the external connectors are only connected to
the dgpu and to be able to use those external connectors without
issues users need to change the default gpu to the dgpu, resulting in
a hot running laptop and the battery draining much faster.

The goal of this feature is to improve switchable graphics support
under Linux, allowing the igpu to be used as default, allowing maximum
batter life, while keeping everthing working normally. Specifically
the following should all work: external outputs, suspend / resume
(including suspend/resume with external monitors connected / while
docked) and suspending the dgpu when not used.

A secondary goal is to allow people to run graphically demanding
programs on the dgpu by starting them with "DRI_PRIME=1 program", note
that since we do not support dynamic reclocking of nvidia GPUs this
will not always result in a performance improvement.



== Scope ==
* Proposal owners: Fix switchable-graphics related kernel and xorg
bugs, ensure gnome-control-panel "Displays" setting works properly on
switchable-graphics setups

* Other developers: GNOME control-panel developers (if changes are
necessary there)

* Release engineering: N/A (not a System Wide Change)

* List of deliverables: N/A (not a System Wide Change)

* Policies and guidelines: N/A (not a System Wide Change)

* Trademark approval: N/A (not needed for this Change)
-- 
Jan Kuřík
Platform & Fedora Program Manager
Red Hat Czech s.r.o., Purkynova 99/71, 612 45 Brno, Czech Republic

[Bastien Nocera]

----- Original Message -----
>  = Proposed Self Contained Change: Better Switchable Graphics Support
> =
>  https://fedoraproject.org/wiki/Changes/BetterSwitchableGraphicsSupport
>  
>  Change owner(s):
>  * Hans de Goede <hdegoede AT redhat DOT com>
>  
>  All modern laptops have a gpu integrated into their processor (the
>  igpu), some models also have a more powerful dedicated gpu (dgpu),
>  this is called switchable graphics. The goal of this feature is to
>  improve Fedora's support for such laptops.
>  
>  
>  == Detailed Description ==
>  By default all apps will run on the more energy efficient igpu and the
>  OS can choose to switch to the dgpu when more gpu-power is necessary,
>  trading battery time for graphics performance. On most laptops the
>  default gpu can be changed to the dgpu so that everything will always
>  run on the dgpu.
>  
>  Linux support for switchable graphics currently is not very good. E.g.
>  on many laptops some of the external connectors are only connected to
>  the dgpu and to be able to use those external connectors without
>  issues users need to change the default gpu to the dgpu, resulting in
>  a hot running laptop and the battery draining much faster.
>  
>  The goal of this feature is to improve switchable graphics support
>  under Linux, allowing the igpu to be used as default, allowing maximum
>  batter life, while keeping everthing working normally. Specifically
>  the following should all work: external outputs, suspend / resume
>  (including suspend/resume with external monitors connected / while
>  docked) and suspending the dgpu when not used. 
Yep, all this should be automatic.

>  A secondary goal is to allow people to run graphically demanding
>  programs on the dgpu by starting them with "DRI_PRIME=1 program", note
>  that since we do not support dynamic reclocking of nvidia GPUs this
>  will not always result in a performance improvement. 
I have some WIP code for gnome-shell to allow that, and it would detect
whether prime is available through a D-Bus service (which also runs a
few hacks for some devices):
https://github.com/hadess/switcheroo-control

>  == Scope ==
>  * Proposal owners: Fix switchable-graphics related kernel and xorg
>  bugs, ensure gnome-control-panel "Displays" setting works properly on
>  switchable-graphics setups
>  
>  * Other developers: GNOME control-panel developers (if changes are
>  necessary there) 
Shouldn't be necessary, though it would be nice if the display adapters
available trickled down from the switcheroo D-Bus service all the way
to gnome-session and then the Details panel in GNOME.

See also:
https://wiki.gnome.org/Design/OS/DualGPU

Cheers