When it comes to the real-time "RT" patches carried outside of the Linux kernel, a number of them pertain to adjustments around the Intel i915 kernel DRM graphics driver. The mainline Linux kernel and its RT support depend upon not building "PREEMPT_RT" for the i915 driver support while patches have been worked on recently for making this Intel kernel graphics driver code play nicely with real-time Linux.

For the RT patches , nearly half of them pertain to Intel i915 driver adjustments that hopefully soon will no longer be necessary with proper fixes being worked on for the mainline kernel.

Maarten Lankhorst today sent out the latest revision of the patches for fixing the i915 driver to "work well" with PREEMPT_RT. There is a caveat in the "work well" that it's fixes for the i915 module without the display support. As part of the current patch series though, it doesn't take it to the step of dropping the " depends on !PREEMPT_RT " Kconfig line currently set for the i915 driver.

In any event those interested in this work to make the Intel i915 kernel driver work well in a real-time Linux world can find today's patch series on the dri-devel list . Once these i915 patches make it to the mainline kernel, it mostly leaves some PowerPC patches as needing to be fixed/upstreamed before the external RT patch queue will be nearly zeroed out.