[RFC 0/3] Enable darkscreen detection

[Suraj Kandpal]

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 at intel.com>

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

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2.43.2