[Intel-gfx] [PATCH 0/4] gen9 dmc state harderning

Mika Kuoppala mika.kuoppala at linux.intel.com
Thu Feb 18 15:21:10 UTC 2016

There have been problems on losing state sync between dmc
and driver. I belive the interplay with racy hw access due to
intel_display_power_is_enabled() with overlapping reprogramming of
allowed dc states (DC_STATE_EN) made DMC very confused.

Imre has now get rid of the troublesome intel_display_power_is_enabled().
On my tests, that is a prerequisite for keeping dmc healthy. But as we
can see from CI/bat, it is still not enough. Sometimes the write still
doesn't stick. So here are dcm state tracking patches.

With these on top of Imre's patches, I have been able to make skl/dmc (v1.23)
symptom free on dc state keeping. With the expection that sometimes we still
need to write the dc_state_en twice. The runaway situation of dmc
not obeying the write, stucking the flip and eventually killing the gpu
is gone.


Mika Kuoppala (3):
  drm/i915/gen9: Verify and enforce dc6 state writes
  drm/i915/gen9: Extend dmc debug mask to include cores
  drm/i915/gen9: Write dc state debugmask bits only once

Patrik Jakobsson (1):
  drm/i915/gen9: Check for DC state mismatch

 drivers/gpu/drm/i915/i915_drv.h         |  1 +
 drivers/gpu/drm/i915/i915_reg.h         |  1 +
 drivers/gpu/drm/i915/intel_csr.c        | 10 +++--
 drivers/gpu/drm/i915/intel_drv.h        |  2 +-
 drivers/gpu/drm/i915/intel_runtime_pm.c | 67 +++++++++++++++++++++++++++------
 5 files changed, 65 insertions(+), 16 deletions(-)


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