When CONFIG_USB is not set, and CONFIG_USB_GADGET is set,
there is an issue, e.g.:
drivers/usb/mtu3/mtu3_debugfs.o: in function 'ssusb_debugfs_create_root':
mtu3_debugfs.c:(.text+0xba3): undefined reference to 'usb_debug_root'
usb_debug_root is currently only built when host is supported
(CONFIG_USB is set), for convenience, we also want it created when
gadget only is enabled, this patch try to support it.
Reported-by: Randy Dunlap <rdun...@infradead.org>
Signed-off-by: Chunfeng Yun <chunfeng....@mediatek.com>
---
v4:
move common API into common.c suggested by Felipe
v3:
1. still create usb_debug_root for gadget only
2. abandon mtu3's change
3. drop acked-by Randy
v2(resend): add acked-by Randy
v1: fix mtu3's build error, replace usb_debug_root by NULL;
---
drivers/usb/common/common.c | 26 ++++++++++++++++++++++++++
drivers/usb/core/usb.c | 16 ++++------------
drivers/usb/gadget/udc/core.c | 3 +++
include/linux/usb.h | 2 ++
4 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index 18f5dcf58b0d..c52e9c9f58ec 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -15,6 +15,7 @@
#include <linux/usb/of.h>
#include <linux/usb/otg.h>
#include <linux/of_platform.h>
+#include <linux/debugfs.h>
static const char *const ep_type_names[] = {
[USB_ENDPOINT_XFER_CONTROL] = "ctrl",
@@ -139,6 +140,31 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev)
}
EXPORT_SYMBOL_GPL(usb_get_dr_mode);
+struct dentry *usb_debug_root;
+EXPORT_SYMBOL_GPL(usb_debug_root);
+
+static atomic_t usb_debug_root_refcnt = ATOMIC_INIT(0);
+
+struct dentry *usb_debugfs_init(void)
+{
+ if (!usb_debug_root)
+ usb_debug_root = debugfs_create_dir("usb", NULL);
+
+ atomic_inc(&usb_debug_root_refcnt);
+
+ return usb_debug_root;
+}
+EXPORT_SYMBOL_GPL(usb_debugfs_init);
+
+void usb_debugfs_cleanup(void)
+{
+ if (atomic_dec_and_test(&usb_debug_root_refcnt)) {
+ debugfs_remove_recursive(usb_debug_root);
+ usb_debug_root = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(usb_debugfs_cleanup);
+
#ifdef CONFIG_OF
/**
* of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 7fcb9f782931..9d8db7faf75f 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -1185,19 +1185,11 @@ static struct notifier_block usb_bus_nb = {
.notifier_call = usb_bus_notify,
};
-struct dentry *usb_debug_root;
-EXPORT_SYMBOL_GPL(usb_debug_root);
-
-static void usb_debugfs_init(void)
+static void usb_core_debugfs_init(void)
{
- usb_debug_root = debugfs_create_dir("usb", NULL);
- debugfs_create_file("devices", 0444, usb_debug_root, NULL,
- &usbfs_devices_fops);
-}
+ struct dentry *root = usb_debugfs_init();
-static void usb_debugfs_cleanup(void)
-{
- debugfs_remove_recursive(usb_debug_root);
+ debugfs_create_file("devices", 0444, root, NULL, &usbfs_devices_fops);
}
/*
@@ -1212,7 +1204,7 @@ static int __init usb_init(void)
}
usb_init_pool_max();
- usb_debugfs_init();
+ usb_core_debugfs_init();
usb_acpi_register();
retval = bus_register(&usb_bus_type);
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 7cf34beb50df..8ef000b9baa4 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1597,12 +1597,15 @@ static int __init usb_udc_init(void)
}
udc_class->dev_uevent = usb_udc_uevent;
+ usb_debugfs_init();
+
return 0;
}
subsys_initcall(usb_udc_init);
static void __exit usb_udc_exit(void)
{
+ usb_debugfs_cleanup();
class_destroy(udc_class);
}
module_exit(usb_udc_exit);
diff --git a/include/linux/usb.h b/include/linux/usb.h
index ae82d9d1112b..175e4a0b1847 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1995,6 +1995,8 @@ extern void usb_unregister_notify(struct notifier_block
*nb);
/* debugfs stuff */
extern struct dentry *usb_debug_root;
+extern struct dentry *usb_debugfs_init(void);
+extern void usb_debugfs_cleanup(void);
/* LED triggers */
enum usb_led_event {
--
2.21.0
