linux: Don't throw an error if there's no data to read

The initial "refresh" for devices would fail if there was no data to
read. Instead, we should set the level to unknown, so that the device
appears in the Power panel, and in the "upower -d" output.

1 files changed, 19 insertions, 33 deletions

diff --git a/src/linux/up-device-supply.c b/src/linux/up-device-supply.c
index d2d2e24..9341cb0 100644
--- a/src/linux/up-device-supply.c
+++ b/src/linux/up-device-supply.c
@@ -47,6 +47,12 @@
 /* number of old energy values to keep cached */
 #define UP_DEVICE_SUPPLY_ENERGY_OLD_LENGTH		4
 
+typedef enum {
+	REFRESH_RESULT_FAILURE = 0,
+	REFRESH_RESULT_SUCCESS = 1,
+	REFRESH_RESULT_NO_DATA
+} RefreshResult;
+
 struct UpDeviceSupplyPrivate
 {
 	guint			 poll_timer_id;
@@ -67,12 +73,7 @@ G_DEFINE_TYPE (UpDeviceSupply, up_device_supply, UP_TYPE_DEVICE)
 
 static gboolean		 up_device_supply_refresh	 	(UpDevice *device);
 
-/**
- * up_device_supply_refresh_line_power:
- *
- * Return %TRUE on success, %FALSE if we failed to refresh or no data
- **/
-static gboolean
+static RefreshResult
 up_device_supply_refresh_line_power (UpDeviceSupply *supply)
 {
 	UpDevice *device = UP_DEVICE (supply);
@@ -89,7 +90,7 @@ up_device_supply_refresh_line_power (UpDeviceSupply *supply)
 	native_path = g_udev_device_get_sysfs_path (native);
 	g_object_set (device, "online", sysfs_get_int (native_path, "online"), NULL);
 
-	return TRUE;
+	return REFRESH_RESULT_SUCCESS;
 }
 
 /**
@@ -516,17 +517,11 @@ sysfs_get_capacity_level (const char    *native_path,
 	return ret;
 }
 
-/**
- * up_device_supply_refresh_battery:
- *
- * Return %TRUE on success, %FALSE if we failed to refresh or no data
- **/
-static gboolean
+static RefreshResult
 up_device_supply_refresh_battery (UpDeviceSupply *supply,
 				  UpDeviceState  *out_state)
 {
 	gchar *technology_native = NULL;
-	gboolean ret = TRUE;
 	gdouble voltage_design;
 	UpDeviceState old_state;
 	UpDeviceState state;
@@ -845,7 +840,7 @@ out:
 	g_free (manufacturer);
 	g_free (model_name);
 	g_free (serial_number);
-	return ret;
+	return REFRESH_RESULT_SUCCESS;
 }
 
 static GUdevDevice *
@@ -893,16 +888,10 @@ up_device_supply_get_sibling_with_subsystem (GUdevDevice *device,
 	return sibling;
 }
 
-/**
- * up_device_supply_refresh_device:
- *
- * Return %TRUE on success, %FALSE if we failed to refresh or no data
- **/
-static gboolean
+static RefreshResult
 up_device_supply_refresh_device (UpDeviceSupply *supply,
 				 UpDeviceState  *out_state)
 {
-	gboolean ret = TRUE;
 	UpDeviceState state;
 	UpDevice *device = UP_DEVICE (supply);
 	const gchar *native_path;
@@ -966,7 +955,7 @@ up_device_supply_refresh_device (UpDeviceSupply *supply,
 		state = UP_DEVICE_STATE_UNKNOWN;
 		g_object_set (device, "state", state, NULL);
 		*out_state = state;
-		return FALSE;
+		return REFRESH_RESULT_NO_DATA;
 	}
 
 	state = up_device_supply_get_state (native_path);
@@ -990,7 +979,7 @@ up_device_supply_refresh_device (UpDeviceSupply *supply,
 
 	*out_state = state;
 
-	return ret;
+	return REFRESH_RESULT_SUCCESS;
 }
 
 static gboolean
@@ -1073,6 +1062,7 @@ up_device_supply_coldplug (UpDevice *device)
 	const gchar *native_path;
 	const gchar *scope;
 	UpDeviceKind type;
+	RefreshResult ret;
 
 	up_device_supply_reset_values (supply);
 
@@ -1127,7 +1117,8 @@ up_device_supply_coldplug (UpDevice *device)
 		up_daemon_start_poll (G_OBJECT (device), (GSourceFunc) up_device_supply_refresh);
 
 	/* coldplug values */
-	return up_device_supply_refresh (device);
+	ret = up_device_supply_refresh (device);
+	return (ret != REFRESH_RESULT_FAILURE);
 }
 
 /**
@@ -1166,15 +1157,10 @@ up_device_supply_disable_unknown_poll (UpDevice *device)
 	}
 }
 
-/**
- * up_device_supply_refresh:
- *
- * Return %TRUE on success, %FALSE if we failed to refresh or no data
- **/
 static gboolean
 up_device_supply_refresh (UpDevice *device)
 {
-	gboolean ret;
+	RefreshResult ret;
 	UpDeviceSupply *supply = UP_DEVICE_SUPPLY (device);
 	UpDeviceKind type;
 	UpDeviceState state;
@@ -1195,10 +1181,10 @@ up_device_supply_refresh (UpDevice *device)
 	}
 
 	/* reset time if we got new data */
-	if (ret)
+	if (ret == REFRESH_RESULT_SUCCESS)
 		g_object_set (device, "update-time", (guint64) g_get_real_time () / G_USEC_PER_SEC, NULL);
 
-	return ret;
+	return (ret != REFRESH_RESULT_FAILURE);
 }
 
 /**