diff --git a/drivers/net/wireless/ath/ath9k/dfs.c b/drivers/net/wireless/ath/ath9k/dfs.c
index 857bb28b389411ea2e1586abd3f5c749c0127327..5049bec5c676c8cf5500702437c8674374bf9478 100644
--- a/drivers/net/wireless/ath/ath9k/dfs.c
+++ b/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);
diff --git a/drivers/net/wireless/ath/ath9k/dfs_debug.h b/drivers/net/wireless/ath/ath9k/dfs_debug.h
index 7936c9126a20d5dee79cae53bb2a06cdb78ed881..d9486867a5e00f089de4adb08989a59470ad26d7 100644
--- a/drivers/net/wireless/ath/ath9k/dfs_debug.h
+++ b/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)