1 files changed, 24 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 2cd97d1cc920..3c7bb0410b51 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -701,7 +701,7 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 {
         struct drm_device *dev = (struct drm_device *) arg;
         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
-        u32 de_iir, gt_iir, de_ier, pm_iir;
+        u32 de_iir, gt_iir, de_ier, pm_iir, sde_ier;
         irqreturn_t ret = IRQ_NONE;
         int i;
 
@@ -711,6 +711,15 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
         de_ier = I915_READ(DEIER);
         I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
 
+        /* Disable south interrupts. We'll only write to SDEIIR once, so further
+         * interrupts will will be stored on its back queue, and then we'll be
+         * able to process them after we restore SDEIER (as soon as we restore
+         * it, we'll get an interrupt if SDEIIR still has something to process
+         * due to its back queue). */
+        sde_ier = I915_READ(SDEIER);
+        I915_WRITE(SDEIER, 0);
+        POSTING_READ(SDEIER);
+
         gt_iir = I915_READ(GTIIR);
         if (gt_iir) {
                 snb_gt_irq_handler(dev, dev_priv, gt_iir);
@@ -759,6 +768,8 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
 
         I915_WRITE(DEIER, de_ier);
         POSTING_READ(DEIER);
+        I915_WRITE(SDEIER, sde_ier);
+        POSTING_READ(SDEIER);
 
         return ret;
 }
@@ -778,7 +789,7 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg)
         struct drm_device *dev = (struct drm_device *) arg;
         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
         int ret = IRQ_NONE;
-        u32 de_iir, gt_iir, de_ier, pm_iir;
+        u32 de_iir, gt_iir, de_ier, pm_iir, sde_ier;
 
         atomic_inc(&dev_priv->irq_received);
 
@@ -787,6 +798,15 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg)
         I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
         POSTING_READ(DEIER);
 
+        /* Disable south interrupts. We'll only write to SDEIIR once, so further
+         * interrupts will will be stored on its back queue, and then we'll be
+         * able to process them after we restore SDEIER (as soon as we restore
+         * it, we'll get an interrupt if SDEIIR still has something to process
+         * due to its back queue). */
+        sde_ier = I915_READ(SDEIER);
+        I915_WRITE(SDEIER, 0);
+        POSTING_READ(SDEIER);
+
         de_iir = I915_READ(DEIIR);
         gt_iir = I915_READ(GTIIR);
         pm_iir = I915_READ(GEN6_PMIIR);
@@ -849,6 +869,8 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg)
 done:
         I915_WRITE(DEIER, de_ier);
         POSTING_READ(DEIER);
+        I915_WRITE(SDEIER, sde_ier);
+        POSTING_READ(SDEIER);
 
         return ret;
 }