On Fri, 2012-10-05 at 16:07 -0700, Eric Anholt wrote: > Imre Deak <imre.deak at intel.com> writes: > > > This is needed to make applications depending on vblank/page flip > > timestamps independent of time ajdustments. > > > > I've tested these with an updated intel-gpu-test/flip_test and will send > > the update for that once there's no objection about this patchset. > > > > The patchset is based on danvet's dinq branch with the following > > additional patches from the intel-gfx ML applied: > > drm/i915: paper over a pipe-enable vs pageflip race > > drm/i915: don't frob the vblank ts in finish_page_flip > > drm/i915: call drm_handle_vblank before finish_page_flip > > While people are in pageflip code: > > It would be really, really cool for application tracing if we could get > timestamps out of our swaps that used the TIMESTAMP register that is the > timer used for event tracing on the GPU using GL_ARB_timer_query. Then > you could get decent visualizations of the latency of your rendering. I assume this querying wouldn't be done through the wait_for_vblank or page_flip ioctls, but rather a new ioctl or even through a new perf event? We could add such a new interface later; this patchset is more focused on the above two ioctls. --Imre
