drm/i915: don't queue flips during a flip pending event

Commit Message

Jesse Barnes April 5, 2010, 9:08 p.m. UTC

None

Patch

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6f5e7f5..24853e1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4235,6 +4235,7 @@  static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	unsigned long flags;
 	int pipesrc_reg = (intel_crtc->pipe == 0) ? PIPEASRC : PIPEBSRC;
 	int ret, pipesrc;
+	u32 flip_mask;
 	RING_LOCALS;
 
 	work = kzalloc(sizeof *work, GFP_KERNEL);
@@ -4285,6 +4286,15 @@  static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	atomic_inc(&obj_priv->pending_flip);
 	work->pending_flip_obj = obj;
 
+	if (intel_crtc->plane)
+		flip_mask = I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
+	else
+		flip_mask = I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT;
+
+	/* Wait for any previous flip to finish */
+	while (I915_READ(ISR) & flip_mask)
+		;
+
 	BEGIN_LP_RING(4);
 	if (IS_I965G(dev)) {
 		OUT_RING(MI_DISPLAY_FLIP |