Question about IEEE80211_PROBE_DELAY

[Helmut Schaa <hschaa@suse.de>]

Hi,

I was just playing around with the mac80211 scan-code and stumbled across 
IEEE80211_PROBE_DELAY. I'm a bit curious why this delay is needed due to the 
fact that any driver can set the channel_change_time to any value it needs.

Therefore I simply removed the IEEE80211_PROBE_DELAY (see below) and only used 
the channel_change_time exposed by the driver. I did some tests with the 
iwl4965 and ath5k (reports AR5213A as chipset) driver and did not notice any 
regression.

Could somebody explain to me if the IEEE80211_PROBE_DELAY is needed anymore 
and for which particular reason?

Thanks,
Helmut

--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3853,8 +3853,7 @@ void ieee80211_sta_scan_work(struct work_struct *work)
 		if (skip)
 			break;
 
-		next_delay = IEEE80211_PROBE_DELAY +
-			     usecs_to_jiffies(local->hw.channel_change_time);
+		next_delay = usecs_to_jiffies(local->hw.channel_change_time);
 		local->scan_state = SCAN_SEND_PROBE;
 		break;
 	case SCAN_SEND_PROBE: