Attachment 110958 Details for Bug 86201 – [PATCH] drm/i915: Kill check_power_well() calls

[patch] [PATCH] drm/i915: Kill check_power_well() calls

0001-drm-i915-Kill-check_power_well-calls.patch (text/plain), 2.92 KB, created by Ville Syrjala on 2014-12-17 15:32:26 UTC

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Creator: Ville Syrjala

Created: 2014-12-17 15:32:26 UTC

Size: 2.92 KB

patch

obsolete

>From d19dc2101a3fc510eea6dc7cc88f30e9ffc0fa6a Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
>Date: Wed, 17 Dec 2014 16:38:33 +0200
>Subject: [PATCH] drm/i915: Kill check_power_well() calls
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>pps_{lock,unlock}() call intel_display_power_{get,put}() outside
>pps_mutes to avoid deadlocks with the power_domain mutex. In theory
>during aux transfers we should usually have the relevant power domain
>references already held by some higher level code, so this should not
>result in much overhead (exception being userspace i2c-dev access).
>However thanks to the check_power_well() calls in
>intel_display_power_{get/put}() we end up doing a few Punit reads for
>each aux transfer. Obviously doing this for each byte transferred via
>i2c-over-aux is not a good idea.
>
>I can't think of a good way to keep check_power_well() while eliminating
>the overhead, so let's just remove check_power_well() entirely.
>
>Credit goes to Jani for figuring this out, assuming it helps :)
>
>Cc: Egbert Eich <eich@suse.de>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86201
>Signed-off-by: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>---
> drivers/gpu/drm/i915/intel_runtime_pm.c | 27 ---------------------------
> 1 file changed, 27 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
>index 6aa3a81..39e1b07 100644
>--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
>+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
>@@ -615,29 +615,6 @@ static void chv_pipe_power_well_disable(struct drm_i915_private *dev_priv,
> 		vlv_power_sequencer_reset(dev_priv);
> }
> 
>-static void check_power_well_state(struct drm_i915_private *dev_priv,
>-				   struct i915_power_well *power_well)
>-{
>-	bool enabled = power_well->ops->is_enabled(dev_priv, power_well);
>-
>-	if (power_well->always_on || !i915.disable_power_well) {
>-		if (!enabled)
>-			goto mismatch;
>-
>-		return;
>-	}
>-
>-	if (enabled != (power_well->count > 0))
>-		goto mismatch;
>-
>-	return;
>-
>-mismatch:
>-	I915_STATE_WARN(1, "state mismatch for '%s' (always_on %d hw state %d use-count %d disable_power_well %d\n",
>-		  power_well->name, power_well->always_on, enabled,
>-		  power_well->count, i915.disable_power_well);
>-}
>-
> /**
>  * intel_display_power_get - grab a power domain reference
>  * @dev_priv: i915 device instance
>@@ -669,8 +646,6 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
> 			power_well->ops->enable(dev_priv, power_well);
> 			power_well->hw_enabled = true;
> 		}
>-
>-		check_power_well_state(dev_priv, power_well);
> 	}
> 
> 	power_domains->domain_use_count[domain]++;
>@@ -709,8 +684,6 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> 			power_well->hw_enabled = false;
> 			power_well->ops->disable(dev_priv, power_well);
> 		}
>-
>-		check_power_well_state(dev_priv, power_well);
> 	}
> 
> 	mutex_unlock(&power_domains->lock);
>-- 
>2.0.4
>

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Attachments on bug 86201: 109341 | 109343 | 109670 | 109950 | 110958

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