drm/i915: gen6_enable_rps() wants to be called after ring initialisation

Currently we call gen6_enable_rps() (which writes into the per-ring
register mmio space) from intel_modeset_init_hw() which is called before
we initialise the rings. If we defer intel_modeset_init_hw() until
afterwards (in the intel_modeset_gem_init() phase) all is well.

v2: Rectify ordering of gem vs display HW init upon resume. (Daniel)

v3: Fix up locking. (Paulo)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Smash Paulo's locking fix onto Chris' patch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -624,25 +624,23 @@ static int i915_drm_thaw(struct drm_device *dev)
 
 	/* KMS EnterVT equivalent */
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		if (HAS_PCH_SPLIT(dev))
+			ironlake_init_pch_refclk(dev);
+
 		mutex_lock(&dev->struct_mutex);
 		dev_priv->mm.suspended = 0;
 
 		error = i915_gem_init_hw(dev);
 		mutex_unlock(&dev->struct_mutex);
 
-		if (HAS_PCH_SPLIT(dev))
-			ironlake_init_pch_refclk(dev);
-
+		intel_modeset_init_hw(dev);
 		drm_mode_config_reset(dev);
 		drm_irq_install(dev);
 
 		/* Resume the modeset for every activated CRTC */
 		mutex_lock(&dev->mode_config.mutex);
 		drm_helper_resume_force_mode(dev);
 		mutex_unlock(&dev->mode_config.mutex);
-
-		if (IS_IRONLAKE_M(dev))
-			ironlake_enable_rc6(dev);
 	}
 
 	intel_opregion_init(dev);

drivers/gpu/drm/i915/i915_suspend.c

@@ -876,12 +876,6 @@ int i915_restore_state(struct drm_device *dev)
 		I915_WRITE(IER, dev_priv->saveIER);
 		I915_WRITE(IMR, dev_priv->saveIMR);
 	}
-	mutex_unlock(&dev->struct_mutex);
-
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		intel_modeset_init_hw(dev);
-
-	mutex_lock(&dev->struct_mutex);
 
 	/* Cache mode state */
 	I915_WRITE(CACHE_MODE_0, dev_priv->saveCACHE_MODE_0 | 0xffff0000);

drivers/gpu/drm/i915/intel_display.c

@@ -6658,6 +6658,7 @@ void intel_modeset_init_hw(struct drm_device *dev)
 
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_enable_drps(dev);
+		ironlake_enable_rc6(dev);
 		intel_init_emon(dev);
 	}
 
@@ -6719,17 +6720,14 @@ void intel_modeset_init(struct drm_device *dev)
 	i915_disable_vga(dev);
 	intel_setup_outputs(dev);
 
-	intel_modeset_init_hw(dev);
-
 	INIT_WORK(&dev_priv->idle_work, intel_idle_update);
 	setup_timer(&dev_priv->idle_timer, intel_gpu_idle_timer,
 		    (unsigned long)dev);
 }
 
 void intel_modeset_gem_init(struct drm_device *dev)
 {
-	if (IS_IRONLAKE_M(dev))
-		ironlake_enable_rc6(dev);
+	intel_modeset_init_hw(dev);
 
 	intel_setup_overlay(dev);
 }