GT635m power management with nouveau

English Hardware
#1

Hi everyone, I am on 13.2 and I’d like to know how to configure my gt635m card with nouveau. Can you tell me how to get it powered off at boot and be able to turn it on so that I can launch programs with either optirun / primusrun ? I have bumblebee installed, nouveau blacklisted in my /etc/modprobe.d/50-blacklist.c file. I’ve heard of bbswitch to turn on my card but it seems like it doesn’t work, even with load_state = 0. I’ve also read about vgaswitcheroo but I don’t know if it’s working since I don’t even know how to see if my card is powered on or not !
Can you tell me :

  • how to check whether my gpu is powered on or not
  • how to boot with gpu off
  • how to turn gpu on when needed
  • the whole thing using nouveau (if possible)

Please tell me which files you need me to provide you.
Thanks in advance

#2

I use bumblebee with the Nvidia proprietary driver, so not the same constellation, but similar.

You will need one kernel module, either nouveau or nvidia, to be able to ‘talk’ with your Nvidia card.

Blacklisting nouveau is done, if you want to use the Nvidia driver.
Else the nouveau driver would be first while booting and would ‘occupy’ the interface.
So remove nouveau from your blacklist, if you want to use it.

You can check the power state of your graphics card with:

cat /proc/acpi/bbswitch

I use a power meter to surveil the power consumption of my laptop.
About 15W with the discrete graphics card switched off, 30W at least with it powered on.

Where did you find ‘load_state = 0’ ?

In order to let bbswitch take care of switching on and off the discrete graphics card, the
graphics card must get initialized correctly while booting.

This can only work with the discrete card powered on on boot time.

If powered off, the system won’t reserve the necessary resources for the graphics card.
It doesn’t get the necessary information from the card cut off power and cannot change the resources layout before next time booting.

But right after initialization of the discrete graphics card, bbswitch will switch off the card again until you later call ‘optirun program’,
to use the discrete graphics with your program.

The relevant configuration file is /etc/modprobe.d/50-bbswitch.conf
It should look like this:

options bbswitch load_state=1 unload_state=1

Run mkinitrd before rebooting.