[arch-general] [RFC] Potentially deprecating primus, bumblebee, virtualGL and primus_vk

[Archange]

Le 12/01/2021 à 21:45, Emil Velikov a écrit :
> On Tue, 12 Jan 2021 at 18:24, Archange <archange at archlinux.org> wrote:
>
>> OK, will try to check tomorrow with a friend that has an Optimus laptop.
>>
> Perfect, thanks in advance.
>
> To trigger the event one has to echo into a sysfs file... Don't recall
> exactly, some of the following should be it.
> a) If the nvidia module is driving an fbcon:
>   - echo "0" > /sys/class/vtconsole/vtconX/bind
> b) and/or a combination of the following
>   - echo "remove" (or was it "unbind") > /sys/class/drm/cardX/device/uevent
>   - echo "remove" (or was it "unbind") >
> /sys/class/drm/cardX/device/driver/uevent
>   - echo "1" > /sys/class/drm/cardX/device/driver/unbind

Bad news as expected:

1) If the driver is not loaded before X, the card is not taken into 
account. However unbinding/rebinding works, and PM too when unbinded and 
setting power to auto on the PCI link.

2) If the driver is loaded before X, it works for PRIME. However, the 
card refuse to unbind because it’s in use by X even if nothing is 
actually running on it.

So unless I missed something power management is not achievable for 
pre-Turing card or on pre-Coffee Lake platform when using PRIME offloading.

At this point I can’t see how changing Bumblebee would work for every 
case. The fact is that there is still no good solution for older 
platform that does both PM and performances.

Regards,
Bruno/Archange