/AMDGPUWakeHandler

Kext for disabling a failed AMD GPU after waking up from sleep.

Primary LanguageC++

AMDGPUWakeHandler

This kernel extension disables the AMD GPU after waking up from sleep. It is intended to be used on a 2011 MacBook Pro with a failed AMD GPU.

NOTE: this should only be used with the grub solution (found here) or similar that powers down the discrete GPU before booting macOS, otherwise it will fail to load.

Installation

After building using Xcode, copy the kext to /Library/Extensions and run the following commands from terminal:

sudo chown -R root:wheel /Library/Extensions/AMDGPUWakeHandler.kext
sudo touch /Library/Extensions

Reboot.

Manual loading

If you prefer to load the kext manually, then after building the kext, copy it to a location of your choice and run the following command to change its permissions:

sudo chown -R root:wheel /path/to/AMDGPUWakeHandler.kext

Then when you want to load the kext you can simply run the command:

sudo kextload /path/to/AMDGPUWakeHandler.kext

To unload:

sudo kextunload /path/to/AMDGPUWakeHandler.kext

View logs

To view the logs for the last 24 hours run the following on the terminal:

log show --last 24h --predicate 'senderImagePath contains "AMDGPUWakeHandler"'


Sarang's notes:

I have preferred to go with manual loading as I did with my Linux installation. The way it is setup currently is that you cannot switch off dGPU if it was not initially switched off when you booted, that is not entirely necessary. On my Linux installation I have been switching it off whenever System wakes from sleep (details later). It is completely different thing that macOS High Sierra does not wake up after sleep. But temperature is a real pain..

This kext has all the code to switch off dGPU, just needs to do it unconditionally:

IOService *AMDGPUWakeHandler::probe(IOService *provider,
                                    SInt32 *score)
{
    IOService *result = super::probe(provider, score);
    IOLog("Probing\n");
    //if (get_discrete_state() != 0) {
    //    IOLog("Failed to Load. Discrete GPU was powered on\n");
    //    return 0;
    //}
    return result;
}

Now, do above at your own risk, it works for me so I went with it. Second the builds are just my caches. Be careful if you use them directly, preferably build the project locally (yes after downloading a good 6GB XCode).

kexts directory has two kexts:

  • AMDGPUWakeHandler-force.kext was built by stubbing out above code
  • AMDGPUWakeHandler.kext was built without any modifications

I have used AMDGPUWakeHandler-force.kext without any issues on my MacOS 10.13.6 so far. I can confirm that temperature drops significantly after it.

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