2008-04-21 16:04:42

by Helmut Schaa

[permalink] [raw]
Subject: Question about IEEE80211_PROBE_DELAY

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: