From ea45b2cbf56a4e93e9c5a68b85794e6d79f69fce Mon Sep 17 00:00:00 2001 From: Juuso Oikarinen Date: Mon, 24 Jan 2011 07:01:54 +0100 Subject: wl12xx: Increase scan channel dwell time for passive scans The passive scan channel dwell time currently used is 30-60TU. A typical beacon interval for AP's is 100TU. This leads to a ~30% worst-case probability of finding an AP via passive scanning. For 5GHz bands for DFS frequencies passive scanning is the only scanning option. Hence for these, the probability of finding an AP is very low. To fix this, increase the passive channel scan dwell times (also the early leave value, as 5GHz channels are still typically very silent.) Use a value of 100TU, because that covers most typical AP configurations. Based on testing the probability of finding an AP (100TU beacon interval) on a single scan round are as follows (based on 100 iterations): dwell min/max (TU) | probability ---------------------+------------ 30/60 | 35% 60/60 | 56% 80/80 | 77% 100/100 | 100% Total scan times now and after the change: Region | Before (s) | After (s) -------+------------+---------- 00 | 0.77 | 1.48 FI | 0.95 | 2.01 US | 0.91 | 1.76 Signed-off-by: Juuso Oikarinen Reviewed-by: Luciano Coelho Signed-off-by: Luciano Coelho --- drivers/net/wireless/wl12xx/conf.h | 18 +++++++++--------- drivers/net/wireless/wl12xx/main.c | 4 ++-- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/wl12xx/conf.h b/drivers/net/wireless/wl12xx/conf.h index 135d837cefb1..fd1dac9ab4db 100644 --- a/drivers/net/wireless/wl12xx/conf.h +++ b/drivers/net/wireless/wl12xx/conf.h @@ -1084,30 +1084,30 @@ struct conf_scan_settings { /* * The minimum time to wait on each channel for active scans * - * Range: 0 - 65536 tu + * Range: u32 tu/1000 */ - u16 min_dwell_time_active; + u32 min_dwell_time_active; /* * The maximum time to wait on each channel for active scans * - * Range: 0 - 65536 tu + * Range: u32 tu/1000 */ - u16 max_dwell_time_active; + u32 max_dwell_time_active; /* - * The maximum time to wait on each channel for passive scans + * The minimum time to wait on each channel for passive scans * - * Range: 0 - 65536 tu + * Range: u32 tu/1000 */ - u16 min_dwell_time_passive; + u32 min_dwell_time_passive; /* * The maximum time to wait on each channel for passive scans * - * Range: 0 - 65536 tu + * Range: u32 tu/1000 */ - u16 max_dwell_time_passive; + u32 max_dwell_time_passive; /* * Number of probe requests to transmit on each active scan channel diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c index eda2f3d8edf1..e535e79e269d 100644 --- a/drivers/net/wireless/wl12xx/main.c +++ b/drivers/net/wireless/wl12xx/main.c @@ -279,8 +279,8 @@ static struct conf_drv_settings default_conf = { .scan = { .min_dwell_time_active = 7500, .max_dwell_time_active = 30000, - .min_dwell_time_passive = 30000, - .max_dwell_time_passive = 60000, + .min_dwell_time_passive = 100000, + .max_dwell_time_passive = 100000, .num_probe_reqs = 2, }, .rf = { -- cgit v1.2.3