Revert changes done in commit f6ec948309 ("drm/i915: extend audio
CDCLK>=2*BCLK constraint to more platforms"). Audio drivers
communicate with i915 over HDA bus multiple times during system
boot-up and each of these transactions result in matching
get_power/put_power calls to i915, and depending on the platform,
a modeset change causing visible flicker.
GLK is the only platform with minimum CDCLK significantly lower
than BCLK, and thus for GLK setting a higher CDCLK is mandatory.
For other platforms, minimum CDCLK is close but below 2*BCLK
(e.g. on ICL, CDCLK=176.4kHz with BCLK=96kHz). Spec-wise the constraint
should be set, but in practise no communication errors have been
reported and the downside if set is the flicker observed at boot-time.
Revert to old behaviour until better mechanism to manage
probe-time clocks is available.
The full CDCLK>=2*BCLK constraint is still enforced at pipe
enable time in intel_crtc_compute_min_cdclk().
Bugzilla: https://gitlab.freedesktop.org/drm/intel/issues/913
Fixes: f6ec948309 ("drm/i915: extend audio CDCLK>=2*BCLK constraint to more platforms")
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191231140007.31728-1-kai.vehmanen@linux.intel.com
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