ath9k: non-functional: calculate DFS pulse interval per-wiphy

Systems with multiple DFS channel detectors need to track
timestamp of previous pulse per instance to display the
correct pulse interval.

Since the interval value is used for debug printing only,
this is a non-functional modification.
Signed-off-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/dfs.c

@@ -178,12 +178,12 @@ void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data,
 	pe.ts = mactime;
 	if (ath9k_postprocess_radar_event(sc, &ard, &pe)) {
 		struct dfs_pattern_detector *pd = sc->dfs_detector;
-		static u64 last_ts;
 		ath_dbg(common, DFS,
 			"ath9k_dfs_process_phyerr: channel=%d, ts=%llu, "
 			"width=%d, rssi=%d, delta_ts=%llu\n",
-			pe.freq, pe.ts, pe.width, pe.rssi, pe.ts-last_ts);
-		last_ts = pe.ts;
+			pe.freq, pe.ts, pe.width, pe.rssi,
+			pe.ts - sc->debug.stats.dfs_stats.last_ts);
+		sc->debug.stats.dfs_stats.last_ts = pe.ts;
 		DFS_STAT_INC(sc, pulses_processed);
 		if (pd != NULL && pd->add_pulse(pd, &pe)) {
 			DFS_STAT_INC(sc, radar_detected);

drivers/net/wireless/ath/ath9k/dfs_debug.h

@@ -51,6 +51,7 @@ struct ath_dfs_stats {
 	/* pattern detection stats */
 	u32 pulses_processed;
 	u32 radar_detected;
+	u64 last_ts;
 };
 
 #if defined(CONFIG_ATH9K_DFS_DEBUGFS)