apple-bce

Buffer Copy Engine fork for Intel Macs with a T2 chip.

Required repositories

The suspend fix is a set of three parts. You will need to replace stock apple-bce with this fork. Additionally you will need the following forks:

• t2-upower: https://github.com/deqrocks/t2-upower
• t2-kbd-tb: https://github.com/deqrocks/t2-kbd-tb

Required kernel parameters

These kernel parameters have to be set in Linux commandline:

• mem_sleep_default=deep as override for hardcoded arguments (if exist)
• pcie_ports=auto as override for hardcoded arguments (if exist)
• pm_async=off to fix a PM race condition caused by aaudio

Notes for dGPU models

On dGPU Macs, suspend may still fail or resume may take very long unless the iGPU is set as the default GPU.

• Follow the iGPU setup from https://wiki.t2linux.org/guides/hybrid-graphics/#enabling-the-igpu
• On Fedora, rebuild both grub and initramfs after changing kernel parameters or module config
• If resume still hangs, try modprobe.blacklist=amdgpu
• Blacklisting amdgpu can make suspend work, but you will lose normal dGPU use and external monitor support
• apple-gmux can be used to force the iGPU as default:

echo "options apple-gmux force_igd=y" | sudo tee /etc/modprobe.d/apple-gmux.conf

Switch back to the dGPU default by changing y to n and rebooting.

Tested Macs

• MacBookAir8,1
• MacBookAir9,1
• MacBookPro15,1
• MacBookPro16,1
• MacBookPro16,2
• MacBookPro16,4
• iMac19,1
• Macmini8,1

Build

make

Deploy

sudo make install
sudo depmod -a
sudo reboot

Rebuild grub if your distro uses grub.

Rebuild initramfs if your distro includes these modules there.

Example for Fedora / dracut-based distros:

sudo dracut -f

Don't forget to build and install the other two repos mentioned above.

Support

If this work helps you and you want to support it:

https://www.paypal.com/paypalme/negmaster

Credits

• MCMrArm https://github.com/MCMrARM
• Antoine Sidem https://github.com/clanoftheducks