drm/omap: increase vblank wait timeout

omap_crtc_wait_pending() waits until the config changes have been taken
into use, usually at next vblank. The wait-timeout used is 50ms, which
usually is enough, but in some rare cases not.

As time wait-timeout is just a safety measure for cases where something
is broken, we can just as well increase the timeout considerably.

This patch makes the timeout 250ms.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index f5b19d1..f1cd280 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -80,9 +80,13 @@
 {
 	struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
 
+	/*
+	 * Timeout is set to a "sufficiently" high value, which should cover
+	 * a single frame refresh even on slower displays.
+	 */
 	return wait_event_timeout(omap_crtc->pending_wait,
 				  !omap_crtc->pending,
-				  msecs_to_jiffies(50));
+				  msecs_to_jiffies(250));
 }
 
 /* -----------------------------------------------------------------------------