drm/i915/skl: Make gen8_irq_power_well_post_enable() take a pipe mask

While we only need to restore pipe B/C interrupt registers on BDW when
enabling the power well, skylake a bit more flexible and we'll also need
to restore the pipe A registers as it has its own power well that can be
toggled.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -3169,14 +3169,19 @@ static void gen8_irq_reset(struct drm_device *dev)
 	ibx_irq_reset(dev);
 }
 
-void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv)
+void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
+				     unsigned int pipe_mask)
 {
 	uint32_t extra_ier = GEN8_PIPE_VBLANK | GEN8_PIPE_FIFO_UNDERRUN;
 
 	spin_lock_irq(&dev_priv->irq_lock);
-	GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_B, dev_priv->de_irq_mask[PIPE_B],
+	if (pipe_mask & 1 << PIPE_B)
+		GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_B,
+				  dev_priv->de_irq_mask[PIPE_B],
 				  ~dev_priv->de_irq_mask[PIPE_B] | extra_ier);
-	GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_C, dev_priv->de_irq_mask[PIPE_C],
+	if (pipe_mask & 1 << PIPE_C)
+		GEN8_IRQ_INIT_NDX(DE_PIPE, PIPE_C,
+				  dev_priv->de_irq_mask[PIPE_C],
 				  ~dev_priv->de_irq_mask[PIPE_C] | extra_ier);
 	spin_unlock_irq(&dev_priv->irq_lock);
 }

drivers/gpu/drm/i915/intel_drv.h

@@ -840,7 +840,8 @@ static inline bool intel_irqs_enabled(struct drm_i915_private *dev_priv)
 }
 
 int intel_get_crtc_scanline(struct intel_crtc *crtc);
-void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv);
+void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
+				     unsigned int pipe_mask);
 
 /* intel_crt.c */
 void intel_crt_init(struct drm_device *dev);

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -195,7 +195,8 @@ static void hsw_power_well_post_enable(struct drm_i915_private *dev_priv)
 	vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);
 
 	if (IS_BROADWELL(dev) || (INTEL_INFO(dev)->gen >= 9))
-		gen8_irq_power_well_post_enable(dev_priv);
+		gen8_irq_power_well_post_enable(dev_priv,
+						1 << PIPE_C | 1 << PIPE_B);
 }
 
 static void hsw_set_power_well(struct drm_i915_private *dev_priv,