Intel Graphics Driver Support For Xe3 "Peak Bandwidth Threshold" Feature In Linux 7.3

Intel today sent out their latest batch of kernel graphics driver updates that are ready for staging ahead of next month's Linux 7.3 merge window.

For end-users one of the interesting changes part of this feature pull is a Peak Bandwidth Threshold feature found with Xe3 Panther Lake graphics and newer as a power savings feature. This can reduce power management demands for the latest Xe3 graphics hardware on Linux.

The patches providing this Peak Bandwidth Threshold feature explain:

"On Xe3+, the SoC can lower the fabric frequency when the display needs less bandwidth than the minimum GV point. This threshold is defined as 20 GB/s. The driver can choose to request this threshold when the required data rate falls below it.

Add an extra QGV entry, with both peak bw and derated bw set to 20 GB/s, to the bandwidth info when all of the following hold:
1. The platform is Xe3+.
2. There is at least one existing QGV point.
3. The number of QGV points is below 8 (the maximum).

Once a plane group is found, the driver iterates over all QGV points in that group to find the best match for the required data rate. If the required data rate is below 20 GB/s, it selects the peak bw from this new QGV point (20 GB/s)."

No numbers were provided as part of the patches for indicating the relative power savings benefit.

This week's Intel DRM pull also enables Ultra-High Bit Rate (UHBR) link rates for Thunderbolt tunneled links, adding the blend mode property to all planes supporting alpha blending, and various bug fixes and other enhancements.

More details on this week's feature patches can be found via the pull request.