OMAPDSS: MANAGER/APPLY: Add runtime_pm protection around wait_for_go/vsync functions

If DSS suspends within the functions dss_mgr_wait_for_go(),
dss_mgr_wait_for_go_ovl() or dss_mgr_wait_for_vsync(). It may lose it's clock
and lead to a register access failure.

Request runtime_pm around these functions.

[archit@ti.com: Moved runtime_pm calls to wait_for_go/vsync functions rather
then calling them from omap_dispc_wait_for_irq_interruptible_timeout()]

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/manager.c

@@ -494,6 +494,11 @@ static int dss_mgr_wait_for_vsync(struct omap_overlay_manager *mgr)
 {
 	unsigned long timeout = msecs_to_jiffies(500);
 	u32 irq;
+	int r;
+
+	r = dispc_runtime_get();
+	if (r)
+		return r;
 
 	if (mgr->device->type == OMAP_DISPLAY_TYPE_VENC) {
 		irq = DISPC_IRQ_EVSYNC_ODD;
@@ -505,7 +510,12 @@ static int dss_mgr_wait_for_vsync(struct omap_overlay_manager *mgr)
 		else
 			irq = DISPC_IRQ_VSYNC2;
 	}
-	return omap_dispc_wait_for_irq_interruptible_timeout(irq, timeout);
+
+	r = omap_dispc_wait_for_irq_interruptible_timeout(irq, timeout);
+
+	dispc_runtime_put();
+
+	return r;
 }
 
 int dss_init_overlay_managers(struct platform_device *pdev)