"ThinkPad linux driver reverse engineered" or "lenovo linux driver reverse engineered"
Power management, I2C devices, touchpad, touchscreen, audio, WiFi, bluetooth, etc. Many things besides the GPU. Maybe some of it is open now (Intel parts) but that wasn't always the case.
As another smart person (smoldesu) pointed out here, Lenovo has recently started contributing some updates to the kernel, but the vast majority has been reverse engineered over decades.
The attitude of Linux devs was always to accept that hardware is proprietary/undocumented and get to work on reverse engineering. Then users take it for granted that stuff just works and have no appreciation of the effort that it took to get it working.
"ThinkPad linux driver reverse engineered" or "lenovo linux driver reverse engineered"
Power management, I2C devices, touchpad, touchscreen, audio, WiFi, bluetooth, etc. Many things besides the GPU. Maybe some of it is open now (Intel parts) but that wasn't always the case.
As another smart person (smoldesu) pointed out here, Lenovo has recently started contributing some updates to the kernel, but the vast majority has been reverse engineered over decades.
The attitude of Linux devs was always to accept that hardware is proprietary/undocumented and get to work on reverse engineering. Then users take it for granted that stuff just works and have no appreciation of the effort that it took to get it working.