Nouveau GSP Fix On The Way For Regression That Broke Ampere GPU Support

An earlier fix to the Nouveau open-source NVIDIA kernel graphics driver with the new GPU System Processor (GSP) code path had fixed RTX 20 "Turing" GPU support but inadvertently broke the RTX 30 "Ampere" support. David Airlie sent out an urgent new fix today for addressing that regression in the NVIDIA GSP display code.

With this new fix to the device initialization paths for display handling in the Nouveau GSP driver code, both Turing and Ampere (and the latest Ada) GPUs should now behave correctly when using the GSP firmware and Nouveau's recent option for enabling its use. Airlie explained in today's DRM urgent fix for getting the new code into Linux 6.9 and in turn for Linux 6.8 stable ASAP:

"A previous fix to nouveau devinit on the GSP paths fixed the Turing but broke Ampere, I did some more digging and found the proper fix. Sending it early as I want to make sure it makes the next 6.8 stable kernels to fix the regression.

Regular fixes will be at end of week as usual."

The fix was just a few lines of new code and discovered after looking at NVIDIA's official open-source GPU kernel driver around a register it was checking.

The regression was introduced last month when wokring to fix acceleration for GeForce RTX 2080 Ti GPUs. This code should be into Linux 6.9 Git shortly ahead of next weekend's Linux 6.9-rc4 release and also back-ported to the Linux 6.8 stable kernel in the coming days.