[Intel-gfx] [PATCH 4/8] drm/i915: Only wait for vblank after pipe enabling on gen2

[Chris Wilson]

Later gen can proceed immediately with the modesetting as it is
automatically double-buffered.

References: https://bugs.freedesktop.org/show_bug.cgi?id=34601
Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_display.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2f63999..95f21d1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1618,7 +1618,9 @@ static void intel_disable_plane(struct drm_i915_private *dev_priv,
 
 	I915_WRITE(reg, val & ~DISPLAY_PLANE_ENABLE);
 	intel_flush_display_plane(dev_priv, plane);
-	intel_wait_for_vblank(dev_priv->dev, pipe);
+
+	if (dev_priv->info->gen == 2)
+		intel_wait_for_vblank(dev_priv->dev, pipe);
 }
 
 static void disable_pch_dp(struct drm_i915_private *dev_priv,
-- 
1.7.2.3