Fix brightness control on turning on lcd from AOD

Move restoring default brightness to display-handler.c
 /* LCDON from AOD */
 if (old_level != default_brightness)
    change_brightness_transit(old_level, default_brightness);

Before this patch, auto_brightenss_control() changes brightness
on receiving SPECIFIC_MODE_OFF(0) even when someone holds brightness.
As originally intended, if someone is holding brightness, that
brightness must be maintained even if SPECIFIC_MODE_OFF comes.

But the code which was added in consideration of the AOD state also
worked in hold state, changing brightness unintentionally. The code
restoring default brightness moved to display-handler.c which is
in charge of LCDON and AOD.

By doing this, auto_brightness_control() is now only works within
LCDON state, no need to care about other than LCDON states.

Change-Id: I067b93bfede7e745e631719eea17a3d4c53aa292
Signed-off-by: Youngjae Cho <y0.cho@samsung.com>

2 files changed, 42 insertions, 28 deletions

diff --git a/plugins/wearable/display/auto-brightness-sensorhub.c b/plugins/wearable/display/auto-brightness-sensorhub.c
index a1ae4e94..b3aac8bb 100644
--- a/plugins/wearable/display/auto-brightness-sensorhub.c
+++ b/plugins/wearable/display/auto-brightness-sensorhub.c
@@ -46,9 +46,6 @@ static void change_brightness_transit(int start, int end)
 
 static void set_brightness_level(int level)
 {
-	int old_level = 0;
-	int default_brightness;
-
 	if (pm_cur_state != S_NORMAL)
 		return;
 /*
@@ -63,9 +60,6 @@ static void set_brightness_level(int level)
 		return;
 	}
 
-	backlight_ops.get_brightness(&old_level);
-	default_brightness = backlight_ops.get_default_brt();
-
 	switch (level) {
 	case LBM_LEVEL:
 		/*
@@ -88,15 +82,15 @@ static void set_brightness_level(int level)
 		break;
 	case SPECIFIC_MODE_OFF:
 		/*
-		 * received HBM disable
-		 * unset hbm state and change brightness to setting value
+		 * Disable LBM or HBM.
+		 * If the flag hold is set when disabling LBM, brightness remains
+		 * held brightness. (FYI. HBM and Hold cannot be both enabled, so
+		 * no need to consider hold flag when disabling HBM)
+		 * Otherwise, brightness changes to default or dim brightness
+		 * depending on flag lowdim.
 		 */
 		auto_brightness_control(BR_HBM_OFF, BR_IMPLICIT);
 		auto_brightness_control(BR_LBM_OFF, BR_IMPLICIT);
-
-		/* LCDON from AOD */
-		if (old_level != default_brightness)
-			change_brightness_transit(old_level, default_brightness);
 		break;
 	default:
 		/*
@@ -110,8 +104,6 @@ static void set_brightness_level(int level)
 		auto_brightness_control(BR_SET_BRIGHTNESS, level);
 		break;
 	}
-
-	device_notify(DEVICE_NOTIFIER_LCD_AUTOBRT_SENSING, NULL);
 }
 
 static void set_default_brightness(void)
diff --git a/plugins/wearable/display/display-handler.c b/plugins/wearable/display/display-handler.c
index 281b6ced..67636b36 100644
--- a/plugins/wearable/display/display-handler.c
+++ b/plugins/wearable/display/display-handler.c
@@ -44,20 +44,27 @@ enum charging_lcd_state {
 };
 
 static guint autobrt_timer;
-static bool lcdon_from_aod;
 static int autobrtlevel;
 
-static gboolean display_autobrt_changed(gpointer data)
-{
+static bool aod_clock_displayed; /* True while AOD screen is displayed */
 
+static gboolean lcdon_from_aod_cb(gpointer data)
+{
 	int level = (int) data;
 
 	autobrt_timer = 0;
+	backlight_ops.transit_state(DPMS_ON);
 	display_info.set_brightness_level(level);
 
+	/* lcdon is completed, aod disappered */
+	aod_clock_displayed = false;
+
 	return G_SOURCE_REMOVE;
 }
 
+/* For AOD state, there is race condition between
+ * HomeScreen dbus signal and AutoBrightnessChanged dbus method call.
+ * Cannot decide which one arrives first */
 static GVariant *dbus_autobrightnesschanged(GDBusConnection *conn,
 	const gchar *sender, const gchar *path, const gchar *iface, const gchar *name,
 	GVariant *param, GDBusMethodInvocation *invocation, gpointer user_data)
@@ -74,18 +81,22 @@ static GVariant *dbus_autobrightnesschanged(GDBusConnection *conn,
 	}
 
 	if (display_info.set_brightness_level) {
-		if (autobrt_timer)
+		if (autobrt_timer) {
 			g_source_remove(autobrt_timer);
+			autobrt_timer = 0;
+		}
+
+		device_notify(DEVICE_NOTIFIER_LCD_AUTOBRT_SENSING, NULL);
 
 		/* When display state changes from AOD to LCDON, brightness change
 		 * effect seems sluggish because of heavy load of jobs for turning on
 		 * display. So delay this brightness change a bit to avoid this
 		 * heavy loaded time and therefore make it change smoothly. */
-		if (lcdon_from_aod) {
-			autobrtlevel = level;
-			autobrt_timer = g_timeout_add(200, display_autobrt_changed, (gpointer)level);
-		} else {
-			display_autobrt_changed((gpointer)level);
+		if (aod_clock_displayed) {
+			autobrtlevel = level; /* reserve the level, defer applying */
+			autobrt_timer = g_timeout_add(200, lcdon_from_aod_cb, (gpointer)level);
+		} else { /* S_NORMAL state or LCDON from usual OFF state, not from AOD */
+			display_info.set_brightness_level(level);
 		}
 	} else {
 		ret = -ENOTSUP;
@@ -118,13 +129,24 @@ static void aod_change_signal(GDBusConnection  *conn,
 	/* clock-viewer send "clockchanged" as signal parameter when AOD->LCDON.
 	 * On catching this signal, do change brightness immediately. */
 	if (!strcmp(screen, CLOCK_CHANGED)) {
-		lcdon_from_aod = false;
-		if (autobrt_timer) {
+		/* aod_clock_displayed can be false if this clockchanged siganl arrives after 200ms timeout.
+		 * In this situation, there is noting to do because all the
+		 * brightness-related task, which should have been done in this routine,
+		 * have been performed by timeout callback, lcdon_from_aod_cb(). */
+		if (!aod_clock_displayed)
+			return;
+
+		backlight_ops.transit_state(DPMS_ON);
+		if (autobrt_timer) { /* if there is reserved level, apply it */
 			g_source_remove(autobrt_timer);
-			display_autobrt_changed((gpointer)autobrtlevel);
+			autobrt_timer = 0;
+			display_info.set_brightness_level(autobrtlevel);
 		}
+		/* lcdon is completed, aod disappered */
+		aod_clock_displayed = false;
 	} else if (!strcmp(screen, CLOCK_END)) {
-		lcdon_from_aod = true;
+		/* lcdoff is completed, aod showed up */
+		aod_clock_displayed = true;
 	}
 
 out:
@@ -168,7 +190,7 @@ static void display_handler_init(void *data)
 	prepare_level_handler();
 	register_notifier(DEVICE_NOTIFIER_LCD, display_state_changed);
 
-	lcdon_from_aod = false;
+	aod_clock_displayed = false;
 	ret = subscribe_dbus_signal(NULL,
 				DEVICED_OBJECT_PATH,
 				DEVICED_INTERFACE_NAME,