[PATCH 2/9] drm/i915: Warn if drm_vblank_get() still works after drm_vblank_off()

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Signed-off-by: Ville Syrjälä <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 3da73ef..da318a7 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1305,6 +1305,17 @@ 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;
@@ -3885,6 +3896,8 @@ 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 */
@@ -3921,6 +3934,8 @@ 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