OMAPDSS: APPLY: add op->enabling

When we are enabling an overlay, there's a point in time when the
overlay is not actually enabled yet (nor do we want it to be enabled),
but we do want to check if the configuration for the overlay is valid,
and to calculate correct fifo thresholds for the soon-to-be-enabled
overlay.

Current code handled this in a hacky way, setting op->enabled to true
temporarily when calling functions that need to consider the state when
the overlay is enabled.

This patch makes this a bit cleaner, adding "enabling" field, which is
set when the overlay is not yet enabled but should be considered in the
checks and calculations.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/apply.c

@@ -72,6 +72,12 @@ struct ovl_priv_data {
 	bool enabled;
 	enum omap_channel channel;
 	u32 fifo_low, fifo_high;
+
+	/*
+	 * True if overlay is to be enabled. Used to check and calculate configs
+	 * for the overlay before it is enabled in the HW.
+	 */
+	bool enabling;
 };
 
 struct mgr_priv_data {
@@ -297,7 +303,7 @@ static int dss_check_settings_low(struct omap_overlay_manager *mgr,
 	list_for_each_entry(ovl, &mgr->overlays, list) {
 		op = get_ovl_priv(ovl);
 
-		if (!op->enabled)
+		if (!op->enabled && !op->enabling)
 			oi = NULL;
 		else if (applying && op->user_info_dirty)
 			oi = &op->user_info;
@@ -998,7 +1004,7 @@ static void dss_mgr_setup_fifos(struct omap_overlay_manager *mgr)
 	list_for_each_entry(ovl, &mgr->overlays, list) {
 		op = get_ovl_priv(ovl);
 
-		if (!op->enabled)
+		if (!op->enabled && !op->enabling)
 			continue;
 
 		dss_ovl_setup_fifo(ovl);
@@ -1395,19 +1401,20 @@ int dss_ovl_enable(struct omap_overlay *ovl)
 
 	spin_lock_irqsave(&data_lock, flags);
 
-	op->enabled = true;
+	op->enabling = true;
+
 	r = dss_check_settings(ovl->manager, ovl->manager->device);
-	op->enabled = false;
 	if (r) {
 		DSSERR("failed to enable overlay %d: check_settings failed\n",
 				ovl->id);
 		goto err2;
 	}
 
-	dss_apply_ovl_enable(ovl, true);
-
 	dss_ovl_setup_fifo(ovl);
 
+	op->enabling = false;
+	dss_apply_ovl_enable(ovl, true);
+
 	dss_write_regs();
 	dss_set_go_bits();
 
@@ -1417,6 +1424,7 @@ int dss_ovl_enable(struct omap_overlay *ovl)
 
 	return 0;
 err2:
+	op->enabling = false;
 	spin_unlock_irqrestore(&data_lock, flags);
 err1:
 	mutex_unlock(&apply_lock);