drm/exynos: fixed page flip issue.

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@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

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 e3861ac49295..de818831a511 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 b6a737d196ae..0dbb32bb18a3 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 47961679c447..93846e810e38 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);
 }