airo: Invoke airo_read_wireless_stats() directly

airo_get_wireless_stats() is the iw_handler_if::get_wireless_stats()
callback of this driver. This callback was not allowed to sleep until
commit a160ee69 ("wext: let get_wireless_stats() sleep") in v2.6.32.

airo still delegates the readout to a thread, which is not longer
necessary.

Invoke airo_read_wireless_stats() directly from the callback and remove
the now unused JOB_WSTATS handling.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201101211536.2966644-3-bigeasy@linutronix.de

drivers/net/wireless/cisco/airo.c

@@ -1144,7 +1144,6 @@ static int airo_thread(void *data);
 static void timer_func(struct net_device *dev);
 static int airo_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
 static struct iw_statistics *airo_get_wireless_stats(struct net_device *dev);
-static void airo_read_wireless_stats(struct airo_info *local);
 #ifdef CISCO_EXT
 static int readrids(struct net_device *dev, aironet_ioctl *comp);
 static int writerids(struct net_device *dev, aironet_ioctl *comp);
@@ -1200,7 +1199,6 @@ struct airo_info {
 #define JOB_MIC	5
 #define JOB_EVENT	6
 #define JOB_AUTOWEP	7
-#define JOB_WSTATS	8
 #define JOB_SCAN_RESULTS  9
 	unsigned long jobs;
 	int (*bap_read)(struct airo_info*, __le16 *pu16Dst, int bytelen,
@@ -3155,8 +3153,6 @@ static int airo_thread(void *data)
 			airo_end_xmit11(dev);
 		else if (test_bit(JOB_STATS, &ai->jobs))
 			airo_read_stats(dev);
-		else if (test_bit(JOB_WSTATS, &ai->jobs))
-			airo_read_wireless_stats(ai);
 		else if (test_bit(JOB_PROMISC, &ai->jobs))
 			airo_set_promisc(ai);
 		else if (test_bit(JOB_MIC, &ai->jobs))
@@ -7732,15 +7728,12 @@ static void airo_read_wireless_stats(struct airo_info *local)
 	__le32 *vals = stats_rid.vals;
 
 	/* Get stats out of the card */
-	clear_bit(JOB_WSTATS, &local->jobs);
-	if (local->power.event) {
-		up(&local->sem);
+	if (local->power.event)
 		return;
-	}
+
 	readCapabilityRid(local, &cap_rid, 0);
 	readStatusRid(local, &status_rid, 0);
 	readStatsRid(local, &stats_rid, RID_STATS, 0);
-	up(&local->sem);
 
 	/* The status */
 	local->wstats.status = le16_to_cpu(status_rid.mode);
@@ -7783,15 +7776,10 @@ static struct iw_statistics *airo_get_wireless_stats(struct net_device *dev)
 {
 	struct airo_info *local =  dev->ml_priv;
 
-	if (!test_bit(JOB_WSTATS, &local->jobs)) {
-		/* Get stats out of the card if available */
-		if (down_trylock(&local->sem) != 0) {
-			set_bit(JOB_WSTATS, &local->jobs);
-			wake_up_interruptible(&local->thr_wait);
-		} else
-			airo_read_wireless_stats(local);
+	if (!down_interruptible(&local->sem)) {
+		airo_read_wireless_stats(local);
+		up(&local->sem);
 	}
-
 	return &local->wstats;
 }