Juuso, > -----Original Message----- > From: Juuso Oikarinen [mailto:juuso.oikarinen@xxxxxxxxx] > Sent: Tuesday, October 05, 2010 12:41 AM > To: Gabay, Benzy > Cc: Coelho Luciano (Nokia-MS/Helsinki); linux-wireless@xxxxxxxxxxxxxxx > Subject: RE: [PATCH 24/25] wl1271: Optimize scan duration > > On Tue, 2010-10-05 at 07:30 +0200, ext Gabay, Benzy wrote: > > Juuso, > > > > > > > > From: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx> > > > > > > Currently then dwell times for each channel in scans is set to an > > > overly > > > long value, and excessive number of probe-requests are transmitted > on > > > each > > > channel (for active scans.) > > > > > > Based on testing, comparable results can be received with smaller > > > dwell-time, > > > and, with fever probe-requests - in fact, reducing the number of > probe- > > > requests > > > to 2 seems to increase the number of found results. > > > > I think that this does not making any sense. Less prob requests > should give you back less results. As less beacons/prob responses are > getting back to the station. > > I think also that office with 70 AP is not a normal environment to > test and optimize numbers. > > I would suggest to re-test in a 1-6 AP environment which is making > more sense for both home and enterprise environment. > > We have actually performed more testing than just mentioned here, in > varied environments, and all of the testing seems to indicate that > reducing the number of probe-reqs per channel is not reducing the > number > of acquired results. Instead, in some scenarios, it is increasing the > number of acquired results. > >> I donât know if that is conventional request: can you share the full results and setup details? > We did not see reduction in the probability of finding a specific AP in > a few (one or two) AP environment either. > > The effect seems to be this way because reducing the number of > probe-req's dramatically reduces the noise generated by probe-responses > from AP's on neighbouring channels. > > -Juuso > > > > > > > > > > > Configure more optimal values for per channel dwell times. > Comparison > > > for the > > > different scan configurations (in my current office environment): > > > > > > dwell-time 60000 3x probe-req == ~60 results > > > 40000 3x probe-req == ~50 results > > > 30000 3x probe-req == ~40 results > > > > > > dwell-time 60000 2x probe-req == ~70 results > > > 40000 2x probe-req == ~60 results > > > 30000 2x probe-req == ~58 results > > > > > > The above are results for a cumulative 3 scan run. For individual > > > scans, the > > > number of results drop slightly more. > > > > > > Signed-off-by: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx> > > > Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@xxxxxxxxx> > > > Signed-off-by: Luciano Coelho <luciano.coelho@xxxxxxxxx> > > > --- > > > drivers/net/wireless/wl12xx/wl1271_conf.h | 39 > > > +++++++++++++++++++++++++++++ > > > drivers/net/wireless/wl12xx/wl1271_main.c | 9 ++++++- > > > drivers/net/wireless/wl12xx/wl1271_scan.c | 18 +++++++++--- > > > drivers/net/wireless/wl12xx/wl1271_scan.h | 3 -- > > > 4 files changed, 60 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/net/wireless/wl12xx/wl1271_conf.h > > > b/drivers/net/wireless/wl12xx/wl1271_conf.h > > > index feb493e..ab716f5 100644 > > > --- a/drivers/net/wireless/wl12xx/wl1271_conf.h > > > +++ b/drivers/net/wireless/wl12xx/wl1271_conf.h > > > @@ -1016,6 +1016,44 @@ struct conf_roam_trigger_settings { > > > u8 avg_weight_snr_data; > > > }; > > > > > > +struct conf_scan_settings { > > > + /* > > > + * The minimum time to wait on each channel for active scans > > > + * > > > + * Range: 0 - 65536 tu > > > + */ > > > + u16 min_dwell_time_active; > > > + > > > + /* > > > + * The maximum time to wait on each channel for active scans > > > + * > > > + * Range: 0 - 65536 tu > > > + */ > > > + u16 max_dwell_time_active; > > > + > > > + /* > > > + * The maximum time to wait on each channel for passive scans > > > + * > > > + * Range: 0 - 65536 tu > > > + */ > > > + u16 min_dwell_time_passive; > > > + > > > + /* > > > + * The maximum time to wait on each channel for passive scans > > > + * > > > + * Range: 0 - 65536 tu > > > + */ > > > + u16 max_dwell_time_passive; > > > + > > > + /* > > > + * Number of probe requests to transmit on each active scan > > > channel > > > + * > > > + * Range: u8 > > > + */ > > > + u16 num_probe_reqs; > > > + > > > +}; > > > + > > > struct conf_drv_settings { > > > struct conf_sg_settings sg; > > > struct conf_rx_settings rx; > > > @@ -1024,6 +1062,7 @@ struct conf_drv_settings { > > > struct conf_itrim_settings itrim; > > > struct conf_pm_config_settings pm_config; > > > struct conf_roam_trigger_settings roam_trigger; > > > + struct conf_scan_settings scan; > > > }; > > > > > > #endif > > > diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c > > > b/drivers/net/wireless/wl12xx/wl1271_main.c > > > index 3f4e154..dcbd6f5 100644 > > > --- a/drivers/net/wireless/wl12xx/wl1271_main.c > > > +++ b/drivers/net/wireless/wl12xx/wl1271_main.c > > > @@ -232,7 +232,14 @@ static struct conf_drv_settings default_conf = > { > > > .avg_weight_rssi_data = 10, > > > .avg_weight_snr_beacon = 20, > > > .avg_weight_snr_data = 10 > > > - } > > > + }, > > > + .scan = { > > > + .min_dwell_time_active = 7500, > > > + .max_dwell_time_active = 30000, > > > + .min_dwell_time_passive = 30000, > > > + .max_dwell_time_passive = 60000, > > > + .num_probe_reqs = 2, > > > + }, > > > }; > > > > > > static void __wl1271_op_remove_interface(struct wl1271 *wl); > > > diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.c > > > b/drivers/net/wireless/wl12xx/wl1271_scan.c > > > index 37f9ccb..5c76b79 100644 > > > --- a/drivers/net/wireless/wl12xx/wl1271_scan.c > > > +++ b/drivers/net/wireless/wl12xx/wl1271_scan.c > > > @@ -64,6 +64,7 @@ static int wl1271_get_scan_channels(struct wl1271 > > > *wl, > > > struct basic_scan_channel_params *channels, > > > enum ieee80211_band band, bool passive) > > > { > > > + struct conf_scan_settings *c = &wl->conf.scan; > > > int i, j; > > > u32 flags; > > > > > > @@ -91,10 +92,17 @@ static int wl1271_get_scan_channels(struct > wl1271 > > > *wl, > > > wl1271_debug(DEBUG_SCAN, "beacon_found %d", > > > req->channels[i]->beacon_found); > > > > > > - channels[j].min_duration = > > > - cpu_to_le32(WL1271_SCAN_CHAN_MIN_DURATION); > > > - channels[j].max_duration = > > > - cpu_to_le32(WL1271_SCAN_CHAN_MAX_DURATION); > > > + if (!passive) { > > > + channels[j].min_duration = > > > + cpu_to_le32(c->min_dwell_time_active); > > > + channels[j].max_duration = > > > + cpu_to_le32(c->max_dwell_time_active); > > > + } else { > > > + channels[j].min_duration = > > > + cpu_to_le32(c->min_dwell_time_passive); > > > + channels[j].max_duration = > > > + cpu_to_le32(c->max_dwell_time_passive); > > > + } > > > channels[j].early_termination = 0; > > > channels[j].tx_power_att = req->channels[i]- > > > >max_power; > > > channels[j].channel = req->channels[i]->hw_value; > > > @@ -151,7 +159,7 @@ static int wl1271_scan_send(struct wl1271 *wl, > enum > > > ieee80211_band band, > > > cmd->params.rx_filter_options = > > > cpu_to_le32(CFG_RX_PRSP_EN | CFG_RX_MGMT_EN | > > > CFG_RX_BCN_EN); > > > > > > - cmd->params.n_probe_reqs = WL1271_SCAN_PROBE_REQS; > > > + cmd->params.n_probe_reqs = wl->conf.scan.num_probe_reqs; > > > cmd->params.tx_rate = cpu_to_le32(basic_rate); > > > cmd->params.tid_trigger = 0; > > > cmd->params.scan_tag = WL1271_SCAN_DEFAULT_TAG; > > > diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.h > > > b/drivers/net/wireless/wl12xx/wl1271_scan.h > > > index bb7af2a..6d57127 100644 > > > --- a/drivers/net/wireless/wl12xx/wl1271_scan.h > > > +++ b/drivers/net/wireless/wl12xx/wl1271_scan.h > > > @@ -40,11 +40,8 @@ void wl1271_scan_complete_work(struct > work_struct > > > *work); > > > #define WL1271_SCAN_OPT_ACTIVE 0 > > > #define WL1271_SCAN_OPT_PASSIVE 1 > > > #define WL1271_SCAN_OPT_PRIORITY_HIGH 4 > > > -#define WL1271_SCAN_CHAN_MIN_DURATION 30000 /* TU */ > > > -#define WL1271_SCAN_CHAN_MAX_DURATION 60000 /* TU */ > > > #define WL1271_SCAN_BAND_2_4_GHZ 0 > > > #define WL1271_SCAN_BAND_5_GHZ 1 > > > -#define WL1271_SCAN_PROBE_REQS 3 > > > > > > #define WL1271_SCAN_TIMEOUT 10000 /* msec */ > > > > > > -- > > > > > > > > Thank You > > ========= > > Benzy Gabay > > OMAP-WLAN Lead > > Texas Instruments > ÿô.nlj·Ÿ®‰†+%ŠË±é¥Šwÿº{.nlj·¥Š{±ÿ«zW¬³ø¡Ü}©ž²ÆzÚj:+v‰¨þø®w¥þŠàÞ¨è&¢)ß«a¶Úÿûz¹ÞúŽŠÝjÿŠwèf
