[i915] leave interrupts masked off when not in use.

The interrupt enable register cannot be used to temporarily disable
interrupts, instead use the interrupt mask register.

Note that this change means that a pile of buffers will be left stuck on the
chip as the final interrupts will not be recognized to come and drain things.

1 files changed, 50 insertions, 24 deletions

diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 02191316..fbfc5f46 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -508,7 +508,7 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 	if (dev_priv->sarea_priv)
 	    dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
 
-	I915_WRITE(I915REG_INT_IDENTITY_R, iir);
+	I915_WRITE(I915REG_INT_IDENTITY_R, iir | I915_USER_INTERRUPT);
 	(void) I915_READ(I915REG_INT_IDENTITY_R); /* Flush posted write */
 
 	if (iir & I915_USER_INTERRUPT) {
@@ -550,8 +550,9 @@ void i915_user_irq_on(drm_i915_private_t *dev_priv)
 {
 	DRM_SPINLOCK(&dev_priv->user_irq_lock);
 	if (dev_priv->irq_enabled && (++dev_priv->user_irq_refcount == 1)){
-		dev_priv->irq_enable_reg |= I915_USER_INTERRUPT;
-		I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+		dev_priv->irq_mask_reg &= ~I915_USER_INTERRUPT;
+		I915_WRITE(I915REG_INT_MASK_R, dev_priv->irq_mask_reg);
+		(void) I915_READ (I915REG_INT_ENABLE_R);
 	}
 	DRM_SPINUNLOCK(&dev_priv->user_irq_lock);
 
@@ -560,9 +561,11 @@ void i915_user_irq_on(drm_i915_private_t *dev_priv)
 void i915_user_irq_off(drm_i915_private_t *dev_priv)
 {
 	DRM_SPINLOCK(&dev_priv->user_irq_lock);
+	BUG_ON(dev_priv->user_irq_refcount <= 0);
 	if (dev_priv->irq_enabled && (--dev_priv->user_irq_refcount == 0)) {
-		//		dev_priv->irq_enable_reg &= ~USER_INT_FLAG;
-		//		I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+		dev_priv->irq_mask_reg |= I915_USER_INTERRUPT;
+		I915_WRITE(I915REG_INT_MASK_R, dev_priv->irq_mask_reg);
+		(void) I915_READ(I915REG_INT_MASK_R);
 	}
 	DRM_SPINUNLOCK(&dev_priv->user_irq_lock);
 }
@@ -642,16 +645,17 @@ int i915_enable_vblank(struct drm_device *dev, int plane)
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	int pipe = i915_get_pipe(dev, plane);
 	u32	pipestat_reg = 0;
+	u32	mask_reg = 0;
 	u32	pipestat;
 
 	switch (pipe) {
 	case 0:
 		pipestat_reg = I915REG_PIPEASTAT;
-		dev_priv->irq_enable_reg |= I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
+		mask_reg |= I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
 		break;
 	case 1:
 		pipestat_reg = I915REG_PIPEBSTAT;
-		dev_priv->irq_enable_reg |= I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
+		mask_reg |= I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
 		break;
 	default:
 		DRM_ERROR("tried to enable vblank on non-existent pipe %d\n",
@@ -677,7 +681,11 @@ int i915_enable_vblank(struct drm_device *dev, int plane)
 			     I915_VBLANK_INTERRUPT_STATUS);
 		I915_WRITE(pipestat_reg, pipestat);
 	}
-	I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+	DRM_SPINLOCK(&dev_priv->user_irq_lock);
+	dev_priv->irq_mask_reg &= ~mask_reg;
+	I915_WRITE(I915REG_INT_MASK_R, dev_priv->irq_mask_reg);
+	I915_READ(I915REG_INT_MASK_R);
+	DRM_SPINUNLOCK(&dev_priv->user_irq_lock);
 
 	return 0;
 }
@@ -687,16 +695,17 @@ void i915_disable_vblank(struct drm_device *dev, int plane)
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	int pipe = i915_get_pipe(dev, plane);
 	u32	pipestat_reg = 0;
+	u32	mask_reg = 0;
 	u32	pipestat;
 
 	switch (pipe) {
 	case 0:
 		pipestat_reg = I915REG_PIPEASTAT;
-		dev_priv->irq_enable_reg &= ~I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
+		mask_reg |= I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
 		break;
 	case 1:
 		pipestat_reg = I915REG_PIPEBSTAT;
-		dev_priv->irq_enable_reg &= ~I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
+		mask_reg |= I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
 		break;
 	default:
 		DRM_ERROR("tried to disable vblank on non-existent pipe %d\n",
@@ -704,7 +713,11 @@ void i915_disable_vblank(struct drm_device *dev, int plane)
 		break;
 	}
 
-	I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+	DRM_SPINLOCK(&dev_priv->user_irq_lock);
+	dev_priv->irq_mask_reg |= mask_reg;
+	I915_WRITE(I915REG_INT_MASK_R, dev_priv->irq_mask_reg);
+	(void) I915_READ (I915REG_INT_MASK_R);
+	DRM_SPINUNLOCK(&dev_priv->user_irq_lock);
 	if (pipestat_reg)
 	{
 		pipestat = I915_READ (pipestat_reg);
@@ -716,6 +729,7 @@ void i915_disable_vblank(struct drm_device *dev, int plane)
 		pipestat |= (I915_START_VBLANK_INTERRUPT_STATUS |
 			     I915_VBLANK_INTERRUPT_STATUS);
 		I915_WRITE(pipestat_reg, pipestat);
+		(void) I915_READ(pipestat_reg);
 	}
 }
 
@@ -723,12 +737,27 @@ static void i915_enable_interrupt (struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	
-	dev_priv->irq_enable_reg |= I915_USER_INTERRUPT;
-
-	I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_enable_reg);
+	dev_priv->irq_mask_reg = (I915_USER_INTERRUPT |
+				  I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
+				  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT);
+	I915_WRITE(I915REG_INT_MASK_R, dev_priv->irq_mask_reg);
+	I915_WRITE(I915REG_INT_ENABLE_R, dev_priv->irq_mask_reg);
+	(void) I915_READ (I915REG_INT_ENABLE_R);
 	dev_priv->irq_enabled = 1;
 }
 
+static void i915_disable_interrupt (struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+	
+	I915_WRITE(I915REG_HWSTAM, 0xffffffff);
+	I915_WRITE(I915REG_INT_MASK_R, 0xffffffff);
+	I915_WRITE(I915REG_INT_ENABLE_R, 0);
+	I915_WRITE(I915REG_INT_IDENTITY_R, 0xffffffff);
+	(void) I915_READ (I915REG_INT_IDENTITY_R);
+	dev_priv->irq_enabled = 0;
+}
+
 /* Set the vblank monitor pipe
  */
 int i915_vblank_pipe_set(struct drm_device *dev, void *data,
@@ -934,9 +963,11 @@ void i915_driver_irq_preinstall(struct drm_device * dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 
-	I915_WRITE16(I915REG_HWSTAM, 0xeffe);
-	I915_WRITE16(I915REG_INT_MASK_R, 0x0);
-	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);
+	I915_WRITE(I915REG_HWSTAM, 0xffff);
+	I915_WRITE(I915REG_INT_ENABLE_R, 0x0);
+	I915_WRITE(I915REG_INT_MASK_R, 0xffffffff);
+	I915_WRITE(I915REG_INT_IDENTITY_R, 0xffffffff);
+	(void) I915_READ(I915REG_INT_IDENTITY_R);
 }
 
 int i915_driver_irq_postinstall(struct drm_device * dev)
@@ -950,7 +981,7 @@ int i915_driver_irq_postinstall(struct drm_device * dev)
 
 	DRM_SPININIT(&dev_priv->user_irq_lock, "userirq");
 	dev_priv->user_irq_refcount = 0;
-	dev_priv->irq_enable_reg = 0;
+	dev_priv->irq_mask_reg = 0;
 
 	ret = drm_vblank_init(dev, num_pipes);
 	if (ret)
@@ -977,15 +1008,10 @@ void i915_driver_irq_uninstall(struct drm_device * dev)
 	if (!dev_priv)
 		return;
 
-	dev_priv->irq_enabled = 0;
-	I915_WRITE(I915REG_HWSTAM, 0xffffffff);
-	I915_WRITE(I915REG_INT_MASK_R, 0xffffffff);
-	I915_WRITE(I915REG_INT_ENABLE_R, 0x0);
+	i915_disable_interrupt (dev);
 
 	temp = I915_READ(I915REG_PIPEASTAT);
 	I915_WRITE(I915REG_PIPEASTAT, temp);
 	temp = I915_READ(I915REG_PIPEBSTAT);
 	I915_WRITE(I915REG_PIPEBSTAT, temp);
-	temp = I915_READ(I915REG_INT_IDENTITY_R);
-	I915_WRITE(I915REG_INT_IDENTITY_R, temp);
 }