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* [Intel-gfx] [PATCH v2] drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only
@ 2019-12-31 14:00 Kai Vehmanen
  2019-12-31 14:38 ` [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only (rev2) Patchwork
                   ` (5 more replies)
  0 siblings, 6 replies; 23+ messages in thread
From: Kai Vehmanen @ 2019-12-31 14:00 UTC (permalink / raw)
  To: intel-gfx

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 <kai.vehmanen@linux.intel.com>
---

Notes:
    v2: d'oh, change put_power() as well

 drivers/gpu/drm/i915/display/intel_audio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
index 27710098d056..e406719a6716 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))
@@ -875,7 +875,7 @@ static void i915_audio_component_put_power(struct device *kdev,
 
 	/* Stop forcing CDCLK to 2*BCLK if no need for audio to be powered. */
 	if (--dev_priv->audio_power_refcount == 0)
-		if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
+		if (IS_GEMINILAKE(dev_priv))
 			glk_force_audio_cdclk(dev_priv, false);
 
 	intel_display_power_put(dev_priv, POWER_DOMAIN_AUDIO, cookie);
-- 
2.17.1

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^ permalink raw reply related	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2020-03-13 14:54 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-31 14:00 [Intel-gfx] [PATCH v2] drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only Kai Vehmanen
2019-12-31 14:38 ` [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only (rev2) Patchwork
2019-12-31 20:06 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
2020-01-02 18:28 ` [Intel-gfx] [PATCH v2] drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only Rodrigo Vivi
2020-01-03 15:28   ` Kai Vehmanen
2020-01-06 16:49     ` Matt Roper
2020-03-06 16:45       ` Kai Vehmanen
2020-03-09 10:54         ` Takashi Iwai
2020-03-10 11:20           ` Kai Vehmanen
2020-03-10 13:41           ` Ville Syrjälä
2020-03-10 17:18             ` Kai Vehmanen
2020-03-10 18:25               ` Ville Syrjälä
2020-03-10 19:13                 ` Takashi Iwai
2020-03-11 12:16                   ` Kai Vehmanen
     [not found]                     ` <s5hk13q7uf6.wl-tiwai@suse.de>
2020-03-11 17:04                       ` Kai Vehmanen
2020-03-11 17:21                         ` Takashi Iwai
2020-03-12 17:27                 ` Kai Vehmanen
2020-03-12 17:48                   ` Ville Syrjälä
2020-03-12 17:50                   ` Ville Syrjälä
2020-03-13 14:54                     ` Kai Vehmanen
2020-03-11 20:12 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for drm/i915: Limit audio CDCLK>=2*BCLK constraint back to GLK only (rev3) Patchwork
2020-03-11 20:37 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-03-12 13:05 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork

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