[ath9k-devel] [PATCH] Make ath9k debug mask setting modifiable via /sys/module.

[David Held <drheld@gmail.com>]

Updating /sys/module/ath9k/parameters/debug will update the debug mask
used if debugging is enabled and can be read to see the current mask.

Signed-off-by: David Held <drheld@gmail.com>
---
Ideally there'd be a nicer way to do this. Definitely open to suggestions.

It seems ugly to pull the int out of the struct, but that (and the spinlock to
avoid destruction races) was the best idea I had.

 drivers/net/wireless/ath/ath9k/init.c |   27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 8894e96..5b99fe2 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -21,6 +21,7 @@
 #include <linux/ath9k_platform.h>
 #include <linux/module.h>
 #include <linux/relay.h>
+#include <linux/spinlock.h>
 #include <net/ieee80211_radiotap.h>
 
 #include "ath9k.h"
@@ -37,8 +38,23 @@ MODULE_DESCRIPTION("Support for Atheros 802.11n wireless LAN cards.");
 MODULE_SUPPORTED_DEVICE("Atheros 802.11n WLAN cards");
 MODULE_LICENSE("Dual BSD/GPL");
 
+static DEFINE_SPINLOCK(debug_lock);
 static unsigned int ath9k_debug = ATH_DBG_DEFAULT;
-module_param_named(debug, ath9k_debug, uint, 0);
+static int *ath_common_debug = NULL;
+static int ath9k_update_debug(const char *val, const struct kernel_param *kp) {
+	int ret = param_set_uint(val, kp);
+	if (ret < 0) return ret;
+
+	spin_lock(&debug_lock);
+	if (ath_common_debug) *ath_common_debug = ath9k_debug;
+	spin_unlock(&debug_lock);
+	return 0;
+}
+static const struct kernel_param_ops ath9k_debug_param_ops = {
+	.set = ath9k_update_debug,
+	.get = param_get_uint,
+};
+module_param_cb(debug, &ath9k_debug_param_ops, &ath9k_debug, 0644);
 MODULE_PARM_DESC(debug, "Debugging mask");
 
 int ath9k_modparam_nohwcrypt;
@@ -525,10 +541,14 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
 	common->ah = ah;
 	common->hw = sc->hw;
 	common->priv = sc;
-	common->debug_mask = ath9k_debug;
 	common->btcoex_enabled = ath9k_btcoex_enable == 1;
 	common->disable_ani = false;
 
+	spin_lock(&debug_lock);
+	ath_common_debug = &common->debug_mask;
+	spin_unlock(&debug_lock);
+	common->debug_mask = ath9k_debug;
+
 	/*
 	 * Platform quirks.
 	 */
@@ -875,6 +895,9 @@ static void ath9k_deinit_softc(struct ath_softc *sc)
 void ath9k_deinit_device(struct ath_softc *sc)
 {
 	struct ieee80211_hw *hw = sc->hw;
+	spin_lock(&debug_lock);
+	ath_common_debug = NULL;
+	spin_unlock(&debug_lock);
 
 	ath9k_ps_wakeup(sc);
 
-- 
1.7.10