[PATCH 2/3] drm/i915: Warn if drm_vblank_get() still works after drm_vblank_off()

[ville.syrj...@linux.intel.com]

From: Ville Syrj?l? <ville.syrj...@linux.intel.com>

Signed-off-by: Ville Syrj?l? <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index df58afc..9420f4f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1298,6 +1298,17 @@ static void assert_sprites_disabled(struct 
drm_i915_private *dev_priv,
        }
 }

+static void assert_vblank_disabled(struct intel_crtc *crtc)
+{
+       struct drm_device *dev = crtc->base.dev;
+       enum pipe pipe = crtc->pipe;
+
+       if (WARN_ON(drm_vblank_get(dev, pipe) == 0)) {
+               drm_vblank_put(dev, pipe);
+               drm_vblank_off(dev, pipe);
+       }
+}
+
 static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
 {
        u32 val;
@@ -3863,6 +3874,8 @@ static void intel_crtc_enable_planes(struct drm_crtc 
*crtc)
        int pipe = intel_crtc->pipe;
        int plane = intel_crtc->plane;

+       assert_vblank_disabled(intel_crtc);
+
        intel_enable_primary_hw_plane(dev_priv, plane, pipe);
        intel_enable_planes(crtc);
        /* The fixup needs to happen before cursor is enabled */
@@ -3899,6 +3912,8 @@ static void intel_crtc_disable_planes(struct drm_crtc 
*crtc)
        intel_crtc_update_cursor(crtc, false);
        intel_disable_planes(crtc);
        intel_disable_primary_hw_plane(dev_priv, plane, pipe);
+
+       assert_vblank_disabled(intel_crtc);
 }

 static void ironlake_crtc_enable(struct drm_crtc *crtc)
-- 
1.8.5.5