[Intel-gfx] [PATCH 00/12] drm/i915: add missing display power refs

[Mika Kuoppala]

Imre Deak <imre.deak at intel.com> writes:

> This patchset adds missing display power domain references during
> modeset HW readout, which I noticed via wakeref warnings the
> corresponding HW accesses triggered. The crt and ddi patches have a
> concrete bugzilla reference they fix, I don't know of reports that would
> be fixed by the rest of the patches in the set. On the way I also
> noticed other places which are potentially racy (debugfs CRC, VGA
>  disabling, pipe_assert) so I fixed those up too.
>
> I left the IRQ setup and error capture code as-is: the former happens
> during driver loading and resume, so the power is guaranteed to stay on
> for the whole sequence. For error capture, we decided early on that we
> won't add any locking around these accesses to minimize the chance for
> locking inversions. Also for this we would need to grab a mutex which
> isn't possible on the error capture path.
>
> Mika came up with a very similar fix, since he suspects that it could
> also be related to recent DMC problems. We agreed that I send mine since
> it uses the more optimal rpm_get_if_in_use() helper (and looks more
> polished).

Yes it seems to help a quite alot, although some hardening
of dcstate writes is still needed on top of this patchset.

I didn't find fix for skl_ddb_get_hw_state() on the series
and it looks like it needs the ref also.

Thanks,
-Mika

>
> Imre Deak (12):
>   drm/i915: add helper to get a display power ref if it was already
>     enabled
>   drm/i915: ensure the HW is powered during display pipe HW readout
>   drm/i915/ibx: ensure the HW is powered during PLL HW readout
>   drm/i915: ensure the HW is powered when disabling VGA
>   drm/i915: ensure the HW is powered during HW access in assert_pipe
>   drm/i915/crt: ensure the HW is powered during HW state readout
>   drm/i915/ddi: ensure the HW is powered during HW state readout
>   drm/i915: ensure the HW is powered when accessing the CRC HW block
>   drm/i915/dp: ensure the HW is powered during HW state readout
>   drm/i915/dsi: ensure the HW is powered during HW state readout
>   drm/i915/hdmi: ensure the HW is powered during HW state readout
>   drm/i915/lvds: ensure the HW is powered during HW state readout
>
>  drivers/gpu/drm/i915/i915_debugfs.c     |  28 ++++++--
>  drivers/gpu/drm/i915/intel_crt.c        |  13 +++-
>  drivers/gpu/drm/i915/intel_ddi.c        | 116 ++++++++++++++++++++++----------
>  drivers/gpu/drm/i915/intel_display.c    |  86 ++++++++++++++++-------
>  drivers/gpu/drm/i915/intel_dp.c         |  18 +++--
>  drivers/gpu/drm/i915/intel_drv.h        |   3 +
>  drivers/gpu/drm/i915/intel_dsi.c        |  13 +++-
>  drivers/gpu/drm/i915/intel_hdmi.c       |  14 +++-
>  drivers/gpu/drm/i915/intel_lvds.c       |  14 +++-
>  drivers/gpu/drm/i915/intel_runtime_pm.c | 111 +++++++++++++++++++++++++-----
>  10 files changed, 315 insertions(+), 101 deletions(-)
>
> -- 
> 2.5.0
>
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