Improve igt_assert for timing checks
Submitted by Daniel Vetter
Assigned to Default DRI bug account
We have a lot of timing checks to make sure something happened in a desired intervall, especially around vblank/flip timestamps. Debugging those is really hard, best option to get started is to dump the ftrace flight recorder of what happened (likely shedding some lights on where we stalled).
Could be useful to roll that into an igt_assert_timing macro to do automatically on assert failures.