drm/i915: Re-register PMIC bus access notifier on runtime resume

commit 294cf1af upstream.

intel_uncore_suspend() unregisters the uncore code's PMIC bus access
notifier and gets called on both normal and runtime suspend.

intel_uncore_resume_early() re-registers the notifier, but only on
normal resume. Add a new intel_uncore_runtime_resume() function which
only re-registers the notifier and call that on runtime resume.
Reported-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114135518.15981-2-hdegoede@redhat.com
(cherry picked from commit bedf4d79)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/i915/i915_drv.c

@@ -2591,6 +2591,8 @@ static int intel_runtime_resume(struct device *kdev)
 		ret = vlv_resume_prepare(dev_priv, true);
 	}
 
+	intel_uncore_runtime_resume(dev_priv);
+
 	/*
 	 * No point of rolling back things in case of an error, as the best
 	 * we can do is to hope that things will still work (and disable RPM).

drivers/gpu/drm/i915/intel_uncore.c

@@ -434,6 +434,12 @@ void intel_uncore_resume_early(struct drm_i915_private *dev_priv)
 	i915_check_and_clear_faults(dev_priv);
 }
 
+void intel_uncore_runtime_resume(struct drm_i915_private *dev_priv)
+{
+	iosf_mbi_register_pmic_bus_access_notifier(
+		&dev_priv->uncore.pmic_bus_access_nb);
+}
+
 void intel_uncore_sanitize(struct drm_i915_private *dev_priv)
 {
 	i915.enable_rc6 = sanitize_rc6_option(dev_priv, i915.enable_rc6);

drivers/gpu/drm/i915/intel_uncore.h

@@ -121,6 +121,7 @@ bool intel_uncore_arm_unclaimed_mmio_detection(struct drm_i915_private *dev_priv
 void intel_uncore_fini(struct drm_i915_private *dev_priv);
 void intel_uncore_suspend(struct drm_i915_private *dev_priv);
 void intel_uncore_resume_early(struct drm_i915_private *dev_priv);
+void intel_uncore_runtime_resume(struct drm_i915_private *dev_priv);
 
 u64 intel_uncore_edram_size(struct drm_i915_private *dev_priv);
 void assert_forcewakes_inactive(struct drm_i915_private *dev_priv);