Nouveau Gets A Few Patches Regarding Voltage Control
In his spare time outside of Intel's Open-Source Technology Center, Martin Peres has been working on a few improvements to the Nouveau DRM driver when it comes to voltage controls.
Last night he published Nouveau patches including support for PWM-based volt management to complement the existing voltage control code in Nouveau for hardware using the GPIO mode, support for non-VID-based voltage controllers, and supporting both volt management modes for Kepler hardware. Martin Peres explained, "Most Keplers actually use the GPIO-based voltage management instead of the new PWM-based one. Use the GPIO mode as a fallback as it already gracefully handles the case where no GPIOs exist. All the Maxwells seem to use the PWM method though."
The fourth and final patch added voltage control for GM107, the GeForce GTX 750 / 750 Ti original Maxwell GPUs. However, none of the GeForce GTX 900 "Maxwell" graphics cards are wired up yet to use the new code until he has his hands on the newer graphics cards to confirm the code works there too.
Hopefully this code will be into shape for merging into Linux 4.4, optimistically with other re-clocking / power management related improvements.