Remove broken 'in vblank' accounting

We need to return an accurate vblank count to the callers of
->get_vblank_counter, and in the Intel case the actual frame count
register isn't udpated until the next active line is displayed, so we
need to return one more than the frame count register if we're currently
in a vblank period.

However, none of the various ways of doing this is working yet, so
disable the logic for now.  This may result in a few missed events, but
should fix the hangs some people have seen due to the current code
tripping the wraparound logic in drm_update_vblank_count.

2 files changed, 28 insertions, 7 deletions

diff --git a/shared-core/i915_drv.h b/shared-core/i915_drv.h
index 7a0c0ea1..c92758fa 100644
--- a/shared-core/i915_drv.h
+++ b/shared-core/i915_drv.h
@@ -794,7 +794,11 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
 #define VSYNCSHIFT_B	0x61028
 
 #define HACTIVE_MASK	0x00000fff
+#define VTOTAL_MASK	0x00001fff
+#define VTOTAL_SHIFT	16
 #define VACTIVE_MASK	0x00000fff
+#define VBLANK_END_MASK	0x00001fff
+#define VBLANK_END_SHIFT 16
 #define VBLANK_START_MASK 0x00001fff
 
 #define PP_STATUS	0x61200
diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 56bcac9c..d463f6e6 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -341,22 +341,39 @@ static void i915_vblank_tasklet(struct drm_device *dev)
 		drm_free(swap_hit, sizeof(*swap_hit), DRM_MEM_DRIVER);
 	}
 }
+#if 0
+static int i915_in_vblank(struct drm_device *dev, int pipe)
+{
+	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+	unsigned long pipedsl, vblank, vtotal;
+	unsigned long vbl_start, vbl_end, cur_line;
+
+	pipedsl = pipe ? PIPEBDSL : PIPEADSL;
+	vblank = pipe ? VBLANK_B : VBLANK_A;
+	vtotal = pipe ? VTOTAL_B : VTOTAL_A;
+
+	vbl_start = I915_READ(vblank) & VBLANK_START_MASK;
+	vbl_end = (I915_READ(vblank) >> VBLANK_END_SHIFT) & VBLANK_END_MASK;
+
+	cur_line = I915_READ(pipedsl);
+
+	if (cur_line >= vbl_start)
+		return 1;
 
+	return 0;
+}
+#endif
 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;
 	unsigned long low_frame;
-	unsigned long pipedsl, vblank, vtotal;
 	u32 high1, high2, low, count;
 	int pipe;
 
 	pipe = i915_get_pipe(dev, plane);
 	high_frame = pipe ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
 	low_frame = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
-	pipedsl = pipe ? PIPEBDSL : PIPEADSL;
-	vblank = pipe ? VBLANK_B : VBLANK_A;
-	vtotal = pipe ? VTOTAL_B : VTOTAL_A;
 
 	if (!i915_pipe_enabled(dev, pipe)) {
 	    printk(KERN_ERR "trying to get vblank count for disabled "
@@ -385,10 +402,10 @@ u32 i915_get_vblank_counter(struct drm_device *dev, int plane)
 	 * above regs won't have been updated yet, so return
 	 * an incremented count to stay accurate
 	 */
-	if ((I915_READ(pipedsl) >= (I915_READ(vblank) & VBLANK_START_MASK)) ||
-	    (I915_READ(pipedsl) < (I915_READ(vtotal) & VACTIVE_MASK)))
+#if 0
+	if (i915_in_vblank(dev, pipe))
 		count++;
-
+#endif
 	return count;
 }