Arch Linux

NoMore201

Member

Registered: 2016-03-15

Posts: 7

After suspend, discrete GPU switches on permamently

My laptop with optimus graphic is working great using both bbswitch+bumblebee+nvidia and nouveau, except when I suspend it.

Basically after resuming from suspend, discrete GPU turns on and there's no way to disable it.
When using bbswitch, after resuming the laptop:

[root@example user]# cat /proc/acpi/bbswitch 
0000:04:00.0 ON
[root@example user]# tee /proc/acpi/bbswitch <<<OFF
OFF
[root@example user]# cat /proc/acpi/bbswitch 
0000:04:00.0 ON

When using nouveau, vgaswitcheroo reports the discrete GPU to be off:

# cat /sys/kernel/debug/vgaswitcheroo/switch
 0:IGD:+:Pwr:0000:00:02.0
 1:DIS: :DynOff:0000:01:00.0

but if I check power consumption with powertop, it shows ~11W idle battery discharge rate against the normal ~6W on a fresh boot.
Question is what could be causing the problem? How do I debug it?

PS: none of the workarounds found in the following pages worked
https://wiki.archlinux.org/index.php/hybrid_graphics
https://wiki.archlinux.org/index.php/bu … i_warnings
https://wiki.archlinux.org/index.php/NVIDIA_Optimus