Linux Kernel Seeing Thunderbolt Improvements That Will Help Older Apple Hardware
A set of 28 patches posted today by Intel Linux developer Mika Westerberg would improve the kernel's Thunderbolt software connection manager and particularly help older Apple hardware.
The Thunderbolt software connection manager is used by systems with Light Ridge, Cactus Ridge, and Falcon Ridge Thunderbolt controllers for creating PCI Express tunnels when a device is connected. At present this software connection manager for these older Thunderbolt controllers on various Apple devices only supports creating a single PCI Express tunnel, but with these new patches there is full PCIe daisy chain support up to six devices. Additionally, tunneling is introduced for DisplayPort and P2P networking capabilities.
For newer Alpine Ridge and now Titan Ridge hardware, the manager is also needed for starting the firmware to handle the tunnel creation.
These Thunderbolt improvements can be found currently on the kernel mailing list while we wait to see if the work is in good enough shape for landing with the upcoming Linux 5.1 cycle.