Use of cache is not clear

[cMancio00]

Don't know how to classify it, question or bug.

I wanted to use the new cache feature but I'm unsure that I understood how it works since it doesn't work in my pc.

I have a Dell Inc. Inspiron 16 7610, with i7-11800H a 3050ti and proprietary drivers. Everything works as intended in Integrated, hybrid and nvidia mode.

According to the readme I should be able to switch from Integrated to Nvidia (and viceversa?) without the need to reboot. However I have to reboot all the time.

This is what I've done to use the cache system:

Starting from hybrid mode

sudo envycontrol --cache-create

Using:

sudo envycontrol --cache-query

outputs:

{
    "nvidia_gpu_pci_bus": "PCI:1:0:0"
}

Now the cache is created so I can switch to Integrated mode and reboot with:

sudo envycontrol -s integrated

and then

reboot

After reboot I check that nvidia-smi outputs the error that no drivers are loaded and

envycontrol --query

gives of course integrated.

BTW I am still able to use my external display.

Now I was expecting that using:

sudo envycontrol -s nvidia

will switch mode without rebooting and nvidia-smi will work, but it is not the case.

Am I missing something? Maybe it will work with open source drivers?

Best regards

[klmcwhirter]

The cache is automatically created when you switch away from hybrid mode. There is no need to use the explicit command line options.

Steps

• make sure you are in hybrid mode
• sudo envycontrol -s integrated and reboot
  At this point the cache file has been created and you are in integrated mode.
  You can confirm the cache contents with sudo envycontrol --cache-query

The intent of the cache is to switch directly from integrated mode to nvidia mode without switching to hybrid mode first.
sudo envycontrol -s nvidia and REBOOT! The reboot is required to have the configuration changes take effect.

This works because the dGPU PCI Bus ID is cached so that the information is available when not in hybrid mode. The envycontrol app can then generate the /etc/X11/xorg.conf file with the correct bus id.

See lines switching to nvidia mode that need bus id.

But once those changes have been made, a reboot IS required as usual.

Hope that helps.

[cMancio00]

Thanks for the clarification.
I'll do a pull request to add this information on the README that (in my opinion) it is not clear about this topic.
Best regards

[bayasdev]

Thanks for the clarification.

I'll do a pull request to add this information on the README that (in my opinion) it is not clear about this topic.

Best regards

Thanks @cMancio00, really appreciate it!

[klmcwhirter]

@cMancio00 - I added some review comments to your PR. Please take a look.

Thanks for taking the time to provide feedback!