drm/i915: cache hw power well enabled state

Jesse noticed that the punit communication needed to query the VLV power
well status can cause substantial delays. Since we can query the state
frequently, for example during I2C transfers, maintain a cached version
of the HW state to get rid of this delay.

This fixes at least one reported regression where boot time increased by
~4 seconds due to frequent power well state queries on VLV during eDP
EDID read.

This regression has been introduced in

commit bb4932c4f17b68f34645ffbcf845e4c29d17290b
Author: Imre Deak <imre.deak@intel.com>
Date:   Mon Apr 14 20:24:33 2014 +0300

    drm/i915: vlv: check port power domain instead of only D0 for eDP VDD on

Reported-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 49414d30e8d42d3068cbd21990f1403e3e8b1f5a..a47fbf60b781ce00d8effd45293920d964870653 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -977,6 +977,8 @@ struct i915_power_well {
        bool always_on;
        /* power well enable/disable usage count */
        int count;
+       /* cached hw enabled state */
+       bool hw_enabled;
        unsigned long domains;
        unsigned long data;
        const struct i915_power_well_ops *ops;

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index efd3cf50cb0f6a647d670a0f2a7b886b4e1d0b8a..9188fede99efbc842cc60914029ba16cd8318e35 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12411,8 +12411,8 @@ intel_display_capture_error_state(struct drm_device *dev)
 
        for_each_pipe(i) {
                error->pipe[i].power_domain_on =
-                       intel_display_power_enabled_sw(dev_priv,
-                                                      POWER_DOMAIN_PIPE(i));
+                       intel_display_power_enabled_unlocked(dev_priv,
+                                                          POWER_DOMAIN_PIPE(i));
                if (!error->pipe[i].power_domain_on)
                        continue;
 
@@ -12447,7 +12447,7 @@ intel_display_capture_error_state(struct drm_device *dev)
                enum transcoder cpu_transcoder = transcoders[i];
 
                error->transcoder[i].power_domain_on =
-                       intel_display_power_enabled_sw(dev_priv,
+                       intel_display_power_enabled_unlocked(dev_priv,
                                POWER_DOMAIN_TRANSCODER(cpu_transcoder));
                if (!error->transcoder[i].power_domain_on)
                        continue;

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bda0ae3d80cc667a5f2706fade10ed58825d34ff..eaa27ee9e3675606a0e2ef17f7f1134060394c68 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -950,8 +950,8 @@ int intel_power_domains_init(struct drm_i915_private *);
 void intel_power_domains_remove(struct drm_i915_private *);
 bool intel_display_power_enabled(struct drm_i915_private *dev_priv,
                                 enum intel_display_power_domain domain);
-bool intel_display_power_enabled_sw(struct drm_i915_private *dev_priv,
-                                   enum intel_display_power_domain domain);
+bool intel_display_power_enabled_unlocked(struct drm_i915_private *dev_priv,
+                                         enum intel_display_power_domain domain);
 void intel_display_power_get(struct drm_i915_private *dev_priv,
                             enum intel_display_power_domain domain);
 void intel_display_power_put(struct drm_i915_private *dev_priv,

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 54242e4f6f4c8cebe2722ca20db0e609fe3c1465..9ad0c6afc48725ca5eb5a050e238055ba4571693 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5603,8 +5603,8 @@ static bool hsw_power_well_enabled(struct drm_i915_private *dev_priv,
                     (HSW_PWR_WELL_ENABLE_REQUEST | HSW_PWR_WELL_STATE_ENABLED);
 }
 
-bool intel_display_power_enabled_sw(struct drm_i915_private *dev_priv,
-                                   enum intel_display_power_domain domain)
+bool intel_display_power_enabled_unlocked(struct drm_i915_private *dev_priv,
+                                         enum intel_display_power_domain domain)
 {
        struct i915_power_domains *power_domains;
        struct i915_power_well *power_well;
@@ -5615,16 +5615,19 @@ bool intel_display_power_enabled_sw(struct drm_i915_private *dev_priv,
                return false;
 
        power_domains = &dev_priv->power_domains;
+
        is_enabled = true;
+
        for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
                if (power_well->always_on)
                        continue;
 
-               if (!power_well->count) {
+               if (!power_well->hw_enabled) {
                        is_enabled = false;
                        break;
                }
        }
+
        return is_enabled;
 }
 
@@ -5632,30 +5635,15 @@ bool intel_display_power_enabled(struct drm_i915_private *dev_priv,
                                 enum intel_display_power_domain domain)
 {
        struct i915_power_domains *power_domains;
-       struct i915_power_well *power_well;
-       bool is_enabled;
-       int i;
-
-       if (dev_priv->pm.suspended)
-               return false;
+       bool ret;
 
        power_domains = &dev_priv->power_domains;
 
-       is_enabled = true;
-
        mutex_lock(&power_domains->lock);
-       for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
-               if (power_well->always_on)
-                       continue;
-
-               if (!power_well->ops->is_enabled(dev_priv, power_well)) {
-                       is_enabled = false;
-                       break;
-               }
-       }
+       ret = intel_display_power_enabled_unlocked(dev_priv, domain);
        mutex_unlock(&power_domains->lock);
 
-       return is_enabled;
+       return ret;
 }
 
 /*
@@ -5976,6 +5964,7 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
                if (!power_well->count++) {
                        DRM_DEBUG_KMS("enabling %s\n", power_well->name);
                        power_well->ops->enable(dev_priv, power_well);
+                       power_well->hw_enabled = true;
                }
 
                check_power_well_state(dev_priv, power_well);
@@ -6005,6 +5994,7 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 
                if (!--power_well->count && i915.disable_power_well) {
                        DRM_DEBUG_KMS("disabling %s\n", power_well->name);
+                       power_well->hw_enabled = false;
                        power_well->ops->disable(dev_priv, power_well);
                }
 
@@ -6267,8 +6257,11 @@ static void intel_power_domains_resume(struct drm_i915_private *dev_priv)
        int i;
 
        mutex_lock(&power_domains->lock);
-       for_each_power_well(i, power_well, POWER_DOMAIN_MASK, power_domains)
+       for_each_power_well(i, power_well, POWER_DOMAIN_MASK, power_domains) {
                power_well->ops->sync_hw(dev_priv, power_well);
+               power_well->hw_enabled = power_well->ops->is_enabled(dev_priv,
+                                                                    power_well);
+       }
        mutex_unlock(&power_domains->lock);
 }