New Intel Hardware Context Support Patches

Arriving this weekend for the open-source Intel DRM graphics driver for the Linux kernel were new -- nearly re-written -- hardware context support patches.

Back in February I wrote about Intel GPU hardware context support patches being published by Ben Widawsky, after he initially worked on the support more than a year ago. He's renewed his work on these patches since the hardware context support is needed for OpenGL transform feedback in the presence of geometry shaders and other items. This hardware context support work targets "Gen4" through "Gen6/7" (Sandy Bridge and Ivy Bridge) graphics. Hardware contexts make it easy for the GPU to save and restore certain state between batch-buffer boundaries rather than needing to re-emit the entire state each time.

This weekend there's new context support patches by Widawsky, but it's not a "version 2" of February's patch-set. Rather, the patches in the past month seen very invasive changes to incorporate comments and feedback from the Intel driver developers. "The patches have changed quite a bit since the RFC, and therefore I didn't feel comfortable trying to do v2 information. I didn't feel comfortable taking the few r-bs that I had from the RFC except for the one patch that I applied wholesale."

The new set of 18 patches can be found on the Intel mailing list. However, it doesn't look like this 800 lines worth of changes is ready for merging into the Linux 3.4 kernel. Ben mentioned that there seems to be missed IRQ issues when running Piglit. At least though there's lots of other DRM changes to find in the Linux 3.4 kernel.