@@ -160,6 +160,42 @@ struct dentry *wwan_get_debugfs_dir(struct device *parent)
return wwandev->debugfs_dir;
}
EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir);
+
+static int wwan_dev_debugfs_match(struct device *dev, const void *dir)
+{
+ struct wwan_device *wwandev;
+
+ if (dev->type != &wwan_dev_type)
+ return 0;
+
+ wwandev = to_wwan_dev(dev);
+
+ return wwandev->debugfs_dir == dir;
+}
+
+static struct wwan_device *wwan_dev_get_by_debugfs(struct dentry *dir)
+{
+ struct device *dev;
+
+ dev = class_find_device(wwan_class, NULL, dir, wwan_dev_debugfs_match);
+ if (!dev)
+ return ERR_PTR(-ENODEV);
+
+ return to_wwan_dev(dev);
+}
+
+void wwan_put_debugfs_dir(struct dentry *dir)
+{
+ struct wwan_device *wwandev = wwan_dev_get_by_debugfs(dir);
+
+ if (WARN_ON(IS_ERR(wwandev)))
+ return;
+
+ /* wwan_dev_get_by_debugfs() also got a reference */
+ put_device(&wwandev->dev);
+ put_device(&wwandev->dev);
+}
+EXPORT_SYMBOL_GPL(wwan_put_debugfs_dir);
#endif
/* This function allocates and registers a new WWAN device OR if a WWAN device
@@ -174,11 +174,13 @@ void wwan_unregister_ops(struct device *parent);
#ifdef CONFIG_WWAN_DEBUGFS
struct dentry *wwan_get_debugfs_dir(struct device *parent);
+void wwan_put_debugfs_dir(struct dentry *dir);
#else
static inline struct dentry *wwan_get_debugfs_dir(struct device *parent)
{
return ERR_PTR(-ENODEV);
}
+static inline void wwan_put_debugfs_dir(struct dentry *dir) {}
#endif
#endif /* __WWAN_H */
WWAN driver call's wwan_get_debugfs_dir() to obtain WWAN debugfs dir entry. As part of this procedure it returns a reference to a found device. Since there is no debugfs interface available at WWAN subsystem, it is not possible to drop dev reference post debugfs use. This leads to side effects like post wwan driver load and reload the wwan instance gets increment from wwanX to wwanX+1. A new debugfs interface is added in wwan subsystem so that wwan driver can drop the obtained dev reference post debugfs use. void wwan_put_debugfs_dir(struct dentry *dir) Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com> --- drivers/net/wwan/wwan_core.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/wwan.h | 2 ++ 2 files changed, 37 insertions(+)