Revert changes done in commit f6ec9483091f ("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 Signed-off-by: Kai Vehmanen <[email protected]> --- drivers/gpu/drm/i915/display/intel_audio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c index 27710098d056..2c5f9b23f286 100644 --- a/drivers/gpu/drm/i915/display/intel_audio.c +++ b/drivers/gpu/drm/i915/display/intel_audio.c @@ -856,7 +856,7 @@ static unsigned long i915_audio_component_get_power(struct device *kdev) } /* Force CDCLK to 2*BCLK as long as we need audio powered. */ - if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) + if (IS_GEMINILAKE(dev_priv)) glk_force_audio_cdclk(dev_priv, true); if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) -- 2.17.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
