i915 irq fixes

Ack the IRQs correctly (PIPExSTAT first followed by IIR).  Don't read
vblank counter registers on disabled pipes (might hang otherwise).  And
deal with flipped pipe/plane mappings if present.

1 files changed, 87 insertions, 32 deletions

diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 9b46b127..bef73b62 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -42,9 +42,9 @@
  * @dev: DRM device
  * @plane: plane to look for
  *
- * We need to get the pipe associated with a given plane to correctly perform
- * vblank driven swapping, and they may not always be equal.  So look up the
- * pipe associated with @plane here.
+ * The Intel Mesa & 2D drivers call the vblank routines with a plane number
+ * rather than a pipe number, since they may not always be equal.  This routine
+ * maps the given @plane back to a pipe number.
  */
 static int
 i915_get_pipe(struct drm_device *dev, int plane)
@@ -58,6 +58,46 @@ i915_get_pipe(struct drm_device *dev, int plane)
 }
 
 /**
+ * i915_get_plane - return the the plane associated with a given pipe
+ * @dev: DRM device
+ * @pipe: pipe to look for
+ *
+ * The Intel Mesa & 2D drivers call the vblank routines with a plane number
+ * rather than a plane number, since they may not always be equal.  This routine
+ * maps the given @pipe back to a plane number.
+ */
+static int
+i915_get_plane(struct drm_device *dev, int pipe)
+{
+	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+
+	if (i915_get_pipe(dev, 0) == pipe)
+		return 0;
+	return 1;
+}
+
+/**
+ * i915_pipe_enabled - check if a pipe is enabled
+ * @dev: DRM device
+ * @pipe: pipe to check
+ *
+ * Reading certain registers when the pipe is disabled can hang the chip.
+ * Use this routine to make sure the PLL is running and the pipe is active
+ * before reading such registers if unsure.
+ */
+static int
+i915_pipe_enabled(struct drm_device *dev, int pipe)
+{
+	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+	unsigned long pipeconf = pipe ? PIPEBCONF : PIPEACONF;
+
+	if (I915_READ(pipeconf) & PIPEACONF_ENABLE)
+		return 1;
+
+	return 0;
+}
+
+/**
  * Emit a synchronous flip.
  *
  * This function must be called with the drawable spinlock held.
@@ -146,14 +186,14 @@ static void i915_vblank_tasklet(struct drm_device *dev)
 	list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
 		drm_i915_vbl_swap_t *vbl_swap =
 			list_entry(list, drm_i915_vbl_swap_t, head);
-		int crtc = i915_get_pipe(dev, vbl_swap->plane);
+		int pipe = i915_get_pipe(dev, vbl_swap->plane);
 
-		if ((counter[crtc] - vbl_swap->sequence) > (1<<23))
+		if ((counter[pipe] - vbl_swap->sequence) > (1<<23))
 			continue;
 
 		list_del(list);
 		dev_priv->swaps_pending--;
-		drm_vblank_put(dev, crtc);
+		drm_vblank_put(dev, pipe);
 
 		DRM_SPINUNLOCK(&dev_priv->swaps_lock);
 		DRM_SPINLOCK(&dev->drw_lock);
@@ -304,12 +344,23 @@ static void i915_vblank_tasklet(struct drm_device *dev)
 	}
 }
 
-u32 i915_get_vblank_counter(struct drm_device *dev, int crtc)
+u32 i915_get_vblank_counter(struct drm_device *dev, int plane)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
-	unsigned long high_frame = crtc ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
-	unsigned long low_frame = crtc ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
+	unsigned long high_frame;
+	unsigned long low_frame;
 	u32 high1, high2, low, count;
+	int pipe;
+
+	pipe = i915_get_pipe(dev, plane);
+	high_frame = pipe ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
+	low_frame = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
+
+	if (!i915_pipe_enabled(dev, pipe)) {
+	    printk(KERN_ERR "trying to get vblank count for disabled "
+		   "pipe %d\n", pipe);
+	    return 0;
+	}
 
 	/*
 	 * High & low register fields aren't synchronized, so make sure
@@ -348,6 +399,23 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 	if (temp == 0)
 		return IRQ_NONE;
 
+	/*
+	 * Clear the PIPE(A|B)STAT regs before the IIR otherwise
+	 * we may get extra interrupts.
+	 */
+	if (temp & VSYNC_PIPEA_FLAG) {
+		drm_handle_vblank(dev, i915_get_plane(dev, 0));
+		I915_WRITE(I915REG_PIPEASTAT,
+			   pipea_stats | I915_VBLANK_INTERRUPT_ENABLE |
+			   I915_VBLANK_CLEAR);
+	}
+	if (temp & VSYNC_PIPEB_FLAG) {
+		drm_handle_vblank(dev, i915_get_plane(dev, 1));
+		I915_WRITE(I915REG_PIPEBSTAT,
+			   pipeb_stats | I915_VBLANK_INTERRUPT_ENABLE |
+			   I915_VBLANK_CLEAR);
+	}
+
 	I915_WRITE16(I915REG_INT_IDENTITY_R, temp);
 	(void) I915_READ16(I915REG_INT_IDENTITY_R); /* Flush posted write */
 
@@ -363,24 +431,9 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 #endif
 	}
 
-	/*
-	 * Use drm_update_vblank_counter here to deal with potential lost
-	 * interrupts
-	 */
-	if (temp & VSYNC_PIPEA_FLAG)
-		drm_handle_vblank(dev, 0);
-	if (temp & VSYNC_PIPEB_FLAG)
-		drm_handle_vblank(dev, 1);
-
 	if (temp & (VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG)) {
 		if (dev_priv->swaps_pending > 0)
 			drm_locked_tasklet(dev, i915_vblank_tasklet);
-		I915_WRITE(I915REG_PIPEASTAT,
-			pipea_stats|I915_VBLANK_INTERRUPT_ENABLE|
-			I915_VBLANK_CLEAR);
-		I915_WRITE(I915REG_PIPEBSTAT,
-			pipeb_stats|I915_VBLANK_INTERRUPT_ENABLE|
-			I915_VBLANK_CLEAR);
 	}
 
 	return IRQ_HANDLED;
@@ -494,11 +547,12 @@ int i915_irq_wait(struct drm_device *dev, void *data,
 	return i915_wait_irq(dev, irqwait->irq_seq);
 }
 
-int i915_enable_vblank(struct drm_device *dev, int crtc)
+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);
 
-	switch (crtc) {
+	switch (pipe) {
 	case 0:
 		dev_priv->irq_enable_reg |= VSYNC_PIPEA_FLAG;
 		break;
@@ -506,8 +560,8 @@ int i915_enable_vblank(struct drm_device *dev, int crtc)
 		dev_priv->irq_enable_reg |= VSYNC_PIPEB_FLAG;
 		break;
 	default:
-		DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
-			  crtc);
+		DRM_ERROR("tried to enable vblank on non-existent pipe %d\n",
+			  pipe);
 		break;
 	}
 
@@ -516,11 +570,12 @@ int i915_enable_vblank(struct drm_device *dev, int crtc)
 	return 0;
 }
 
-void i915_disable_vblank(struct drm_device *dev, int crtc)
+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);
 
-	switch (crtc) {
+	switch (pipe) {
 	case 0:
 		dev_priv->irq_enable_reg &= ~VSYNC_PIPEA_FLAG;
 		break;
@@ -528,8 +583,8 @@ void i915_disable_vblank(struct drm_device *dev, int crtc)
 		dev_priv->irq_enable_reg &= ~VSYNC_PIPEB_FLAG;
 		break;
 	default:
-		DRM_ERROR("tried to disable vblank on non-existent crtc %d\n",
-			  crtc);
+		DRM_ERROR("tried to disable vblank on non-existent pipe %d\n",
+			  pipe);
 		break;
 	}