b3f74938d6
All timestamps returned by GuC for GuC PMU busyness are captured from GUC PM TIMESTAMP. Since this timestamp does not tick when GuC goes idle, kmd uses RING_TIMESTAMP to measure busyness of an engine with an active context. In further stress testing, the MMIO read of the RING_TIMESTAMP is seen to cause a rare hang. Resolve the issue by using gt specific timestamp from PM which is in sync with the GuC PM timestamp. Fixes:77cdd054dd("drm/i915/pmu: Connect engine busyness stats from GuC to pmu") Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com> Signed-off-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220111015523.225562-1-umesh.nerlige.ramappa@intel.com (cherry picked from commit721fd84ea1) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>