Linux 5.5 To Restore Power-Savings For Hybrid Laptops When Not Using The dGPU

[phoronix]

Phoronix: Linux 5.5 To Restore Power-Savings For Hybrid Laptops When Not Using The dGPU

On recent kernels when using a laptop with hybrid graphics but not running with the discrete GPU graphics enabled, a regression meant the dGPU never got powered off... Fortunately, for Linux 5.5 -- and potentially to be back-ported after that -- is a change to restore that power-savings...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-5.5-dGPU-Sound-Bind-Power

[FireBurn]

**NVIDIA** Laptops, not an issue for AMD ones

[polarathene]

**NVIDIA** Laptops, not an issue for AMD ones

Not as click-baity though

New feature for premium supporters, honest headlines :P

[amdtesterman]

I think is not only for nvidia laptops, Michael do you know if the fix is only for nvidia or amd was having problems too?

[timrichardson]

Well, that explains some help requests on Reddit that made no sense to me. I think that if you have Optimus hardware, you should use Ubuntu or a derivative.

[starshipeleven]

if you are not using the dGPU at all, either disable it from the UEFI settings, or install/use bbswitch https://github.com/Bumblebee-Project/bbswitch

[stormcrow]

if you are not using the dGPU at all, either disable it from the UEFI settings, or install/use bbswitch https://github.com/Bumblebee-Project/bbswitch

Probably not a good idea. Did you look to see when the last commit to that repository was made? "Dec 4, 2013"

Linux has come a long way since then and bbswitch doesn't necessarily work with recent distributions. The only thing really keeping up with kernel changes and new hardware in Linux land is the Nvidia proprietary driver which irritatingly requires a relog to switch between the dGPU and iGPU. Also, not all laptop firmware has the option to disable the dGPU.

[starshipeleven]

Probably not a good idea. Did you look to see when the last commit to that repository was made? "Dec 4, 2013"

did you look at the source? (or did otherwise understand what it is doing)
It's a dkms module doing direct ACPI calls (ACPI is an API provided by the BIOS/UEFI firmware in binary form and is more or less standardized), so it does not care that much about Linux kernel or different NVIDIA cards as it's not interacting much with the former and not at all with the latter.

All it does is ask the UEFI to turn on or off the dGPU. If it does not work (or the GPU fails to start again after you turn it off) it's a board firmware issue. We can discuss that there should be a better way, but bbswitch per-se isn't the one to blame.

In my HP Probook 470 G4 is working. Also packaged by ubuntu and OpenSUSE and others in the main repos (no ppa or third party repos)