Arch Linux

dasBook

Member

Registered: 2015-10-27

Posts: 3

Power-off ATI on MacBookPro 11,5 w/ a blacklisted radeon driver?

I installed Arch on my mid-2015 MacBookPro, in a Linux-only configuration, using systemd-boot, which I believe is the simplest way to do it. My laptop has dual graphics, an Intel and an ATI card:

$ lspci
...
00:02.0 VGA compatible controller: Intel Corporation Crystal Well Integrated Graphics Controller (rev 08)
...
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X/M370X] (rev 83)

However, right after the install process I could only see the API card, driven AFAICT by the radeon module. This was not a problem because it worked flawlessly, including sleeping and waking up, but it draws a lot of power. Off to activate and use the Intel graphics I used apple-set-os EFI program to trick the laptop into showing the Intel graphics. Lo and behold it works, and the vgaswitcheroo folder shows up on the next boot. I then installed gpu-switch program to switch to the Intel card for good, and I was able to power off the ATI card by echo-ing OFF to vgaswitcheroo/switch after I made sure the Intel one is active. All good.

But, I then blacklisted the ATI driver and on the next boot only the Intel card showed up, vgaswitcheroo is no longer present in my /sys mount (as a result of blacklisting, I guess). lspci shows both hardware. X works super on the Intel card, no changes necessary, and glxinfo shows the Intel hardware.

My question is: is the ATI hardware powered off by the blacklisting of the radeon driver or is it on, but merely not accessible? In other words, should I remove the blacklisting and go back to letting Linux load both modules for both hardware, enable vgaswitcheroo, which I would then use to manually power off the ATI hardware?

Lone_Wolf

Member

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 6,593

Re: Power-off ATI on MacBookPro 11,5 w/ a blacklisted radeon driver?

is it on, but merely not accessible?

looking at your post,  apple-set-os and gpu-switch does match with that.

remove the blacklisting and go back to your vgaswitcheroo method.

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Multi-init booting with apg Openrc and systemd coexisting
Automounting : not needed, i prefer pmount
Aur helpers : makepkg + my own local repo === rarely need them