[RFC PATCH 03/14] drm/exynos: use wait_event_timeout() for safety usage

[YoungJun Cho]

There could be the case that the page flip operation isn't finished correctly
with some abnormal condition such as panel reset. So this patch replaces
wait_event() with wait_event_timeout() to avoid waiting for page flip completion
infinitely.

Signed-off-by: YoungJun Cho <yj44.cho at samsung.com>
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 |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
index e930d4f..1419d11 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
@@ -69,8 +69,9 @@ static void exynos_drm_crtc_dpms(struct drm_crtc *crtc, int mode)
 
 	if (mode > DRM_MODE_DPMS_ON) {
 		/* wait for the completion of page flip. */
-		wait_event(exynos_crtc->pending_flip_queue,
-				atomic_read(&exynos_crtc->pending_flip) == 0);
+		wait_event_timeout(exynos_crtc->pending_flip_queue,
+				!atomic_read(&exynos_crtc->pending_flip),
+				HZ/20);
 		drm_vblank_off(crtc->dev, exynos_crtc->pipe);
 	}
 
-- 
1.7.9.5