When HDA controller is resumed from suspend, i915 HDMI/DP
codec requires that following order of actions is kept:
- i915 display power up and configuration of link params
- hda link reset and setup
Current SOF HDA code delegates display codec power control
to the codec driver. This works most of the time, but in
runtime PM sequences, the above constraint may be violated.
On platforms where BIOS values for HDA link parameters do
not match hardware reset defaults, this may lead to errors
in HDA verb transactions after resume.
Fix the issue by explicitly powering the display codec
in the HDA controller resume/suspend calls, thus ensuring
correct ordering. Special handling is needed for the D0i3
flow, where display power must be turned off even though
DSP is left powered.
Now that we have more invocations of the display power helper
functions, the conditional checks surrounding each call have
been moved inside hda_codec_i915_display_power(). The two
special cases of display powering at initial probe are handled
separately. The intent is to avoid powering the display whenever
no display codecs are used.
Note that early powering of display was removed in
commit 687ae9e287 ("ASoC: intel: skl: Fix display power regression").
This change was also copied to the SOF driver. No failures
have resulted as hardware default values for link parameters
have worked out of the box. However with recent i915 driver
changes like done in commit 87c1694533 ("drm/i915: save
AUD_FREQ_CNTRL state at audio domain suspend"), this does not
hold anymore and errors are hit.
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200206200223.7715-2-kai.vehmanen@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
816938b272