Fifo underrun can lead to flicker, screen corruption and blank screen in case of pipe hang. This patch series aims to enable dark screen detection whenever FIFO underruns are hit and in case we face a darkscreen at this point instead of disabling irq and fbc we want to try reset the pipe on which the underrun has occured and keep a track on the number of times underrun occurs post reset and if this persists more than 5 times we go ahead and reset the whole display. If this still persists we then fallback to disabling irq and the fb. To summarize we are using the dark screen detction feature to detect the pipe hung scenario of FIFO underrun. After detection as corrective measurements following is done. 1)pipe reset 2)display reset Comments on this design and ideas on how else this can be implemented or diffrent scenarios dark screen detection can be used are also welcome. Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> Suraj Kandpal (3): drm/i915: Add Dark screen detection registers drm/i915/darkscreen: Enable darkscreen detection drm/i915: Schedule darkscreen detection work drivers/gpu/drm/i915/Makefile | 1 + .../gpu/drm/i915/display/intel_darkscreen.c | 139 ++++++++++++++++++ .../gpu/drm/i915/display/intel_darkscreen.h | 25 ++++ .../drm/i915/display/intel_display_types.h | 3 + .../drm/i915/display/intel_fifo_underrun.c | 2 + drivers/gpu/drm/i915/i915_reg.h | 8 + drivers/gpu/drm/xe/Makefile | 1 + 7 files changed, 179 insertions(+) create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.c create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.h -- 2.43.2
