[PATCH 07/11] drm/exynos: fixed page flip issue.

[Inki Dae]

with vblank_refcount = 1, there was the case that drm_vblank_put
is called by specific page flip function so this patch fixes the
issue.

Signed-off-by: Inki Dae <inki.dae at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_crtc.c |    6 +++---
 drivers/gpu/drm/exynos/exynos_drm_fimd.c |    7 ++++++-
 drivers/gpu/drm/exynos/exynos_mixer.c    |    7 ++++++-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
index e3861ac..de81883 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
@@ -307,9 +307,6 @@ static int exynos_drm_crtc_page_flip(struct drm_crtc *crtc,
 		 */
 		event->pipe = exynos_crtc->pipe;
 
-		list_add_tail(&event->base.link,
-				&dev_priv->pageflip_event_list);
-
 		ret = drm_vblank_get(dev, exynos_crtc->pipe);
 		if (ret) {
 			DRM_DEBUG("failed to acquire vblank counter\n");
@@ -318,6 +315,9 @@ static int exynos_drm_crtc_page_flip(struct drm_crtc *crtc,
 			goto out;
 		}
 
+		list_add_tail(&event->base.link,
+				&dev_priv->pageflip_event_list);
+
 		crtc->fb = fb;
 		ret = exynos_drm_crtc_update(crtc);
 		if (ret) {
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
index b6a737d..0dbb32b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
@@ -604,7 +604,12 @@ static void fimd_finish_pageflip(struct drm_device *drm_dev, int crtc)
 	}
 
 	if (is_checked) {
-		drm_vblank_put(drm_dev, crtc);
+		/*
+		 * call drm_vblank_put only in case that drm_vblank_get was
+		 * called.
+		 */
+		if (atomic_read(&drm_dev->vblank_refcount[crtc]) > 0)
+			drm_vblank_put(drm_dev, crtc);
 
 		/*
 		 * don't off vblank if vblank_disable_allowed is 1,
diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
index 4796167..93846e8 100644
--- a/drivers/gpu/drm/exynos/exynos_mixer.c
+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
@@ -712,7 +712,12 @@ static void mixer_finish_pageflip(struct drm_device *drm_dev, int crtc)
 	}
 
 	if (is_checked)
-		drm_vblank_put(drm_dev, crtc);
+		/*
+		 * call drm_vblank_put only in case that drm_vblank_get was
+		 * called.
+		 */
+		if (atomic_read(&drm_dev->vblank_refcount[crtc]) > 0)
+			drm_vblank_put(drm_dev, crtc);
 
 	spin_unlock_irqrestore(&drm_dev->event_lock, flags);
 }
-- 
1.7.4.1