ath9k: create a common debugfs_root for all device instances

The driver are trying to create an 'ath9k' directory in debugfs for each
device currently. If there are more than one device in the system, the
second try will always fail.

Changes-licensed-under: ISC

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/debug.c b/drivers/net/wireless/ath9k/debug.c
index 8d914221..0f7e249 100644
--- a/drivers/net/wireless/ath9k/debug.c
+++ b/drivers/net/wireless/ath9k/debug.c
@@ -19,6 +19,8 @@
 static unsigned int ath9k_debug = DBG_DEFAULT;
 module_param_named(debug, ath9k_debug, uint, 0);
 
+static struct dentry *ath9k_debugfs_root;
+
 void DPRINTF(struct ath_softc *sc, int dbg_mask, const char *fmt, ...)
 {
 	if (!sc)
@@ -491,12 +493,8 @@
 {
 	sc->debug.debug_mask = ath9k_debug;
 
-	sc->debug.debugfs_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
-	if (!sc->debug.debugfs_root)
-		goto err;
-
 	sc->debug.debugfs_phy = debugfs_create_dir(wiphy_name(sc->hw->wiphy),
-						      sc->debug.debugfs_root);
+						      ath9k_debugfs_root);
 	if (!sc->debug.debugfs_phy)
 		goto err;
 
@@ -538,5 +536,19 @@
 	debugfs_remove(sc->debug.debugfs_interrupt);
 	debugfs_remove(sc->debug.debugfs_dma);
 	debugfs_remove(sc->debug.debugfs_phy);
-	debugfs_remove(sc->debug.debugfs_root);
+}
+
+int ath9k_debug_create_root(void)
+{
+	ath9k_debugfs_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	if (!ath9k_debugfs_root)
+		return -ENOENT;
+
+	return 0;
+}
+
+void ath9k_debug_remove_root(void)
+{
+	debugfs_remove(ath9k_debugfs_root);
+	ath9k_debugfs_root = NULL;
 }
diff --git a/drivers/net/wireless/ath9k/debug.h b/drivers/net/wireless/ath9k/debug.h
index 2a33d74..065268b 100644
--- a/drivers/net/wireless/ath9k/debug.h
+++ b/drivers/net/wireless/ath9k/debug.h
@@ -102,7 +102,6 @@
 
 struct ath9k_debug {
 	int debug_mask;
-	struct dentry *debugfs_root;
 	struct dentry *debugfs_phy;
 	struct dentry *debugfs_dma;
 	struct dentry *debugfs_interrupt;
@@ -114,6 +113,8 @@
 void DPRINTF(struct ath_softc *sc, int dbg_mask, const char *fmt, ...);
 int ath9k_init_debug(struct ath_softc *sc);
 void ath9k_exit_debug(struct ath_softc *sc);
+int ath9k_debug_create_root(void);
+void ath9k_debug_remove_root(void);
 void ath_debug_stat_interrupt(struct ath_softc *sc, enum ath9k_int status);
 void ath_debug_stat_rc(struct ath_softc *sc, struct sk_buff *skb);
 void ath_debug_stat_retries(struct ath_softc *sc, int rix,
@@ -135,6 +136,15 @@
 {
 }
 
+static inline int ath9k_debug_create_root(void)
+{
+	return 0;
+}
+
+static inline void ath9k_debug_remove_root(void)
+{
+}
+
 static inline void ath_debug_stat_interrupt(struct ath_softc *sc,
 					    enum ath9k_int status)
 {
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index f473fee..bb30ccc 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -2858,12 +2858,20 @@
 		goto err_out;
 	}
 
+	error = ath9k_debug_create_root();
+	if (error) {
+		printk(KERN_ERR
+			"ath9k: Unable to create debugfs root: %d\n",
+			error);
+		goto err_rate_unregister;
+	}
+
 	error = ath_pci_init();
 	if (error < 0) {
 		printk(KERN_ERR
 			"ath9k: No PCI devices found, driver not installed.\n");
 		error = -ENODEV;
-		goto err_rate_unregister;
+		goto err_remove_root;
 	}
 
 	error = ath_ahb_init();
@@ -2877,6 +2885,8 @@
  err_pci_exit:
 	ath_pci_exit();
 
+ err_remove_root:
+	ath9k_debug_remove_root();
  err_rate_unregister:
 	ath_rate_control_unregister();
  err_out:
@@ -2888,6 +2898,7 @@
 {
 	ath_ahb_exit();
 	ath_pci_exit();
+	ath9k_debug_remove_root();
 	ath_rate_control_unregister();
 	printk(KERN_INFO "%s: Driver unloaded\n", dev_info);
 }