drm/i915: fix display power sw state reporting

commit b8c000d9bf23e7c1155ef421f595d1cbc25262da upstream.

Atm, we refcount both power domains and power wells and
intel_display_power_enabled_sw() returns the power domain refcount. What
the callers are really interested in though is the sw state of the
underlying power wells. Due to this we will report incorrectly that a
given power domain is off if its power wells were enabled via another
power domain, for example POWER_DOMAIN_INIT which enables all power
wells.

As a fix return instead the state based on the refcount of all power
wells included in the passed in power domain.

References: https://bugs.freedesktop.org/show_bug.cgi?id=79505
References: https://bugs.freedesktop.org/show_bug.cgi?id=79038
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index bd1b003..8e72451 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5138,10 +5138,25 @@ bool intel_display_power_enabled_sw(struct drm_device *dev,
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct i915_power_domains *power_domains;
+       struct i915_power_well *power_well;
+       bool is_enabled;
+       int i;
+
+       if (dev_priv->pm.suspended)
+               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;
 
-       return power_domains->domain_use_count[domain];
+               if (!power_well->count) {
+                       is_enabled = false;
+                       break;
+               }
+       }
+       return is_enabled;
 }
 
 bool intel_display_power_enabled(struct drm_device *dev,