From 034fc31292edaa25779a938ab3e92ef34697eaf9 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
Date: Tue, 5 Sep 2006 14:23:18 +0200
Subject: [PATCH] i915: Only turn on user IRQs when they are needed.

---
 linux-core/i915_fence.c |  8 ++------
 shared-core/i915_drv.h  |  6 ++++++
 shared-core/i915_irq.c  | 34 ++++++++++++++++++++++++++++++++--
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/linux-core/i915_fence.c b/linux-core/i915_fence.c
index 673ebd0e..80ef3ab2 100644
--- a/linux-core/i915_fence.c
+++ b/linux-core/i915_fence.c
@@ -58,13 +58,9 @@ static void i915_perform_flush(drm_device_t * dev)
 			diff = sequence - fm->exe_flush_sequence;
 			if (diff < driver->wrap_diff) {
 				fm->pending_exe_flush = 0;
-				/*
-				 * Turn off user IRQs
-				 */
+				i915_user_irq_off(dev_priv);
 			} else {
-				/*
-				 * Turn on user IRQs
-				 */
+			        i915_user_irq_on(dev_priv);
 			}
 		}
 	}
diff --git a/shared-core/i915_drv.h b/shared-core/i915_drv.h
index 8bf82ed8..f8d08741 100644
--- a/shared-core/i915_drv.h
+++ b/shared-core/i915_drv.h
@@ -103,6 +103,10 @@ typedef struct drm_i915_private {
 	struct mem_block *agp_heap;
 	unsigned int sr01, adpa, ppcr, dvob, dvoc, lvds;
 	int vblank_pipe;
+        spinlock_t user_irq_lock;
+        int user_irq_refcount;
+        uint32_t irq_enable_reg;
+        int irq_enabled;
 
 #ifdef I915_HAVE_FENCE
         uint32_t flush_sequence;
@@ -139,6 +143,8 @@ extern void i915_driver_irq_uninstall(drm_device_t * dev);
 extern int i915_vblank_pipe_set(DRM_IOCTL_ARGS);
 extern int i915_vblank_pipe_get(DRM_IOCTL_ARGS);
 extern int i915_emit_irq(drm_device_t * dev);
+extern void i915_user_irq_on(drm_i915_private_t *dev_priv);
+extern void i915_user_irq_off(drm_i915_private_t *dev_priv);
 
 /* i915_mem.c */
 extern int i915_mem_alloc(DRM_IOCTL_ARGS);
diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 4195555e..a3f6a03b 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -102,6 +102,29 @@ int i915_emit_irq(drm_device_t * dev)
 
 }
 
+void i915_user_irq_on(drm_i915_private_t *dev_priv)
+{
+
+	spin_lock(&dev_priv->user_irq_lock);
+	if (dev_priv->irq_enabled && (++dev_priv->user_irq_refcount > 0)){
+		dev_priv->irq_enable_reg |= USER_INT_FLAG;
+		I915_WRITE16(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+	}
+	spin_unlock(&dev_priv->user_irq_lock);
+
+}
+		
+void i915_user_irq_off(drm_i915_private_t *dev_priv)
+{
+	spin_lock(&dev_priv->user_irq_lock);
+	if (dev_priv->irq_enabled && (--dev_priv->user_irq_refcount == 0)) {
+		dev_priv->irq_enable_reg &= ~USER_INT_FLAG;
+		I915_WRITE16(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+	}
+	spin_unlock(&dev_priv->user_irq_lock);
+}
+		
+
 static int i915_wait_irq(drm_device_t * dev, int irq_nr)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
@@ -114,9 +137,11 @@ static int i915_wait_irq(drm_device_t * dev, int irq_nr)
 		return 0;
 
 	dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;
-
+	
+	i915_user_irq_on(dev_priv);
 	DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
 		    READ_BREADCRUMB(dev_priv) >= irq_nr);
+	i915_user_irq_off(dev_priv);
 
 	if (ret == DRM_ERR(EBUSY)) {
 		DRM_ERROR("%s: EBUSY -- rec: %d emitted: %d\n",
@@ -211,7 +236,11 @@ static int i915_enable_interrupt (drm_device_t *dev)
 			  __FUNCTION__, dev_priv->vblank_pipe);
 		return DRM_ERR(EINVAL);
 	}
-	I915_WRITE16(I915REG_INT_ENABLE_R, USER_INT_FLAG | flag);
+	dev_priv->user_irq_lock = SPIN_LOCK_UNLOCKED;
+	dev_priv->user_irq_refcount = 0;
+	dev_priv->irq_enable_reg = flag;
+	I915_WRITE16(I915REG_INT_ENABLE_R, flag);
+	dev_priv->irq_enabled = 1;
 	return 0;
 }
 
@@ -290,6 +319,7 @@ void i915_driver_irq_uninstall(drm_device_t * dev)
 	if (!dev_priv)
 		return;
 
+	dev_priv->irq_enabled = 0;
 	I915_WRITE16(I915REG_HWSTAM, 0xffff);
 	I915_WRITE16(I915REG_INT_MASK_R, 0xffff);
 	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);