[PATCH v2 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>

v2: Drop the drm_vblank_off() (Daniel)
    Use drm_crtc_vblank_{get,put}()

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3da73ef..94ac51f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1305,6 +1305,12 @@ static void assert_sprites_disabled(struct drm_i915_private *dev_priv,
 	}
 }
 
+static void assert_vblank_disabled(struct drm_crtc *crtc)
+{
+	if (WARN_ON(drm_crtc_vblank_get(crtc) == 0))
+		drm_crtc_vblank_put(crtc);
+}
+
 static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
 {
 	u32 val;
@@ -3885,6 +3891,8 @@ static void intel_crtc_enable_planes(struct drm_crtc *crtc)
 	int pipe = intel_crtc->pipe;
 	int plane = intel_crtc->plane;
 
+	assert_vblank_disabled(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 +3929,8 @@ 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(crtc);
 }
 
 static void ironlake_crtc_enable(struct drm_crtc *crtc)
-- 
1.8.5.5