Commit 76f05d88 authored by M Chetan Kumar's avatar M Chetan Kumar Committed by David S. Miller

net: wwan: debugfs obtained dev reference not dropped

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: default avatarM Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1e997d04
...@@ -160,6 +160,42 @@ struct dentry *wwan_get_debugfs_dir(struct device *parent) ...@@ -160,6 +160,42 @@ struct dentry *wwan_get_debugfs_dir(struct device *parent)
return wwandev->debugfs_dir; return wwandev->debugfs_dir;
} }
EXPORT_SYMBOL_GPL(wwan_get_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 #endif
/* This function allocates and registers a new WWAN device OR if a WWAN device /* 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); ...@@ -174,11 +174,13 @@ void wwan_unregister_ops(struct device *parent);
#ifdef CONFIG_WWAN_DEBUGFS #ifdef CONFIG_WWAN_DEBUGFS
struct dentry *wwan_get_debugfs_dir(struct device *parent); struct dentry *wwan_get_debugfs_dir(struct device *parent);
void wwan_put_debugfs_dir(struct dentry *dir);
#else #else
static inline struct dentry *wwan_get_debugfs_dir(struct device *parent) static inline struct dentry *wwan_get_debugfs_dir(struct device *parent)
{ {
return ERR_PTR(-ENODEV); return ERR_PTR(-ENODEV);
} }
static inline void wwan_put_debugfs_dir(struct dentry *dir) {}
#endif #endif
#endif /* __WWAN_H */ #endif /* __WWAN_H */
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