[RFC PATCH] usb: common: change usb_debug_root as static variable

From: Chunfeng Yun
Date: Thu Oct 31 2019 - 22:29:40 EST


Try to avoid using extern global variable, and provide two
functions for the usage cases

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
NOTE:
Prepared but not send out patches for drivers using usb_debug_root,
because I'm not sure whether this patch is needed, and many drivers
will be modified.
---
drivers/usb/common/common.c | 16 ++++++++++++++--
include/linux/usb.h | 5 ++++-
2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index 1433260d99b4..639ee6d243a2 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -293,8 +293,20 @@ struct device *usb_of_get_companion_dev(struct device *dev)
EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
#endif

-struct dentry *usb_debug_root;
-EXPORT_SYMBOL_GPL(usb_debug_root);
+static struct dentry *usb_debug_root;
+
+struct dentry *usb_debugfs_create_dir(const char *name)
+{
+ return debugfs_create_dir(name, usb_debug_root);
+}
+EXPORT_SYMBOL_GPL(usb_debugfs_create_dir);
+
+struct dentry *usb_debugfs_create_file(const char *name, umode_t mode,
+ void *data, const struct file_operations *fops)
+{
+ return debugfs_create_file(name, mode, usb_debug_root, data, fops);
+}
+EXPORT_SYMBOL_GPL(usb_debugfs_create_file);

static int __init usb_common_init(void)
{
diff --git a/include/linux/usb.h b/include/linux/usb.h
index e656e7b4b1e4..ad96e0aa0127 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -2001,7 +2001,10 @@ extern void usb_register_notify(struct notifier_block *nb);
extern void usb_unregister_notify(struct notifier_block *nb);

/* debugfs stuff */
-extern struct dentry *usb_debug_root;
+extern struct dentry *usb_debugfs_create_dir(const char *name);
+extern struct dentry *
+usb_debugfs_create_file(const char *name, umode_t mode, void *data,
+ const struct file_operations *fops);

/* LED triggers */
enum usb_led_event {
--
2.23.0