[SRU][B/OEM-B/C/D/E][PATCH 0/1] Audio doesn't work after s3 or s4 on cnl and glk machines

[Hui Wang]

BugLink: https://bugs.launchpad.net/bugs/1826868

The patch is already in the v5.2-rc1, so don't send the patch
to unstable.

[Impact]
After s3 or s4, the hdmi audio driver will re-probe the hw, if the hdmi
monitor is not plugged before s3 or s4, the re-probe will fail on cnl
and glk machines.

[Fix]
Keep the cdclk alive when re-probing

[Test Case]
do s3 and s4 without hdmi monitor plugged, after s3 or s4, plug the hdmi
monitor, to check if the hdmi audio works well, it works well indeed.

[Regression Risk]
Low. the 1st patch is specific to cnl and glk machines, and without this patch,
the cdclk is 0, after applying this patch, if hdmi audio want to probe hw, the
patch just set the a non-zero freq on cdclk.


Ville Syrjälä (1):
  drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled

 drivers/gpu/drm/i915/i915_drv.h      |  3 ++
 drivers/gpu/drm/i915/intel_audio.c   | 59 ++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_cdclk.c   | 30 +++++---------
 drivers/gpu/drm/i915/intel_display.c |  9 ++++-
 drivers/gpu/drm/i915/intel_drv.h     |  3 ++
 5 files changed, 83 insertions(+), 21 deletions(-)

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2.17.1