USB: use sysfs_merge_group for power attributes

This patch (as1426) makes use of the new sysfs_merge_group() and
sysfs_unmerge_group() routines to simplify the handling of power
attributes for USB devices.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 17 insertions, 33 deletions

diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 448f5b47fc48..9561e087907d 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -233,8 +233,6 @@ static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);
 
 #ifdef  CONFIG_PM
 
-static const char power_group[] = "power";
-
 static ssize_t
 show_persist(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -278,7 +276,7 @@ static int add_persist_attributes(struct device *dev)
                 if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
                         rc = sysfs_add_file_to_group(&dev->kobj,
                                         &dev_attr_persist.attr,
-                                        power_group);
+                                        power_group_name);
         }
         return rc;
 }
@@ -287,7 +285,7 @@ static void remove_persist_attributes(struct device *dev)
 {
         sysfs_remove_file_from_group(&dev->kobj,
                         &dev_attr_persist.attr,
-                        power_group);
+                        power_group_name);
 }
 #else
 
@@ -438,44 +436,30 @@ set_level(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
 
+static struct attribute *power_attrs[] = {
+        &dev_attr_autosuspend.attr,
+        &dev_attr_level.attr,
+        &dev_attr_connected_duration.attr,
+        &dev_attr_active_duration.attr,
+        NULL,
+};
+static struct attribute_group power_attr_group = {
+        .name   = power_group_name,
+        .attrs  = power_attrs,
+};
+
 static int add_power_attributes(struct device *dev)
 {
         int rc = 0;
 
-        if (is_usb_device(dev)) {
-                rc = sysfs_add_file_to_group(&dev->kobj,
-                                &dev_attr_autosuspend.attr,
-                                power_group);
-                if (rc == 0)
-                        rc = sysfs_add_file_to_group(&dev->kobj,
-                                        &dev_attr_level.attr,
-                                        power_group);
-                if (rc == 0)
-                        rc = sysfs_add_file_to_group(&dev->kobj,
-                                        &dev_attr_connected_duration.attr,
-                                        power_group);
-                if (rc == 0)
-                        rc = sysfs_add_file_to_group(&dev->kobj,
-                                        &dev_attr_active_duration.attr,
-                                        power_group);
-        }
+        if (is_usb_device(dev))
+                rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
         return rc;
 }
 
 static void remove_power_attributes(struct device *dev)
 {
-        sysfs_remove_file_from_group(&dev->kobj,
-                        &dev_attr_active_duration.attr,
-                        power_group);
-        sysfs_remove_file_from_group(&dev->kobj,
-                        &dev_attr_connected_duration.attr,
-                        power_group);
-        sysfs_remove_file_from_group(&dev->kobj,
-                        &dev_attr_level.attr,
-                        power_group);
-        sysfs_remove_file_from_group(&dev->kobj,
-                        &dev_attr_autosuspend.attr,
-                        power_group);
+        sysfs_unmerge_group(&dev->kobj, &power_attr_group);
 }
 
 #else