2014-01-06 07:58:22

by Jouni Malinen

[permalink] [raw]
Subject: [RFC 3/3] mac80211: Allow channel time for scans to be modified

This uses the MaxChannelTime value, if specified, from the scan request
to control how long the mac80211 sw_scan spends on the channels.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/scan.c | 38 +++++++++++++++++++++++++++++---------
1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 88c8161..53252a5 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -29,6 +29,27 @@
#define IEEE80211_CHANNEL_TIME (HZ / 33)
#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)

+static unsigned long ieee80211_scan_active_time(struct ieee80211_local *local)
+{
+ /*
+ * Note: Could use min_chan_time to speed scans if we supported
+ * PHY-CCA.indication detection or maybe an emulation of that based on
+ * frame RX.
+ */
+ if (!local->scan_req->max_chan_time)
+ return IEEE80211_CHANNEL_TIME;
+ return max_t(unsigned long,
+ TU_TO_JIFFIES(local->scan_req->max_chan_time), 1);
+}
+
+static unsigned long ieee80211_scan_passive_time(struct ieee80211_local *local)
+{
+ if (!local->scan_req->max_chan_time)
+ return IEEE80211_PASSIVE_CHANNEL_TIME;
+ return max_t(unsigned long,
+ TU_TO_JIFFIES(local->scan_req->max_chan_time), 1);
+}
+
void ieee80211_rx_bss_put(struct ieee80211_local *local,
struct ieee80211_bss *bss)
{
@@ -447,7 +468,7 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
* After sending probe requests, wait for probe responses
* on the channel.
*/
- *next_delay = IEEE80211_CHANNEL_TIME;
+ *next_delay = ieee80211_scan_active_time(local);
local->next_scan_state = SCAN_DECISION;
}

@@ -489,6 +510,8 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
req->n_channels * sizeof(req->channels[0]);
local->hw_scan_req->ie = ies;
local->hw_scan_req->flags = req->flags;
+ local->hw_scan_req->min_chan_time = req->min_chan_time;
+ local->hw_scan_req->max_chan_time = req->max_chan_time;

local->hw_scan_band = 0;

@@ -527,14 +550,11 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
/* We need to ensure power level is at max for scanning. */
ieee80211_hw_config(local, 0);

- if ((req->channels[0]->flags &
- IEEE80211_CHAN_NO_IR) ||
- !local->scan_req->n_ssids) {
- next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
- } else {
+ if ((req->channels[0]->flags & IEEE80211_CHAN_NO_IR) ||
+ !local->scan_req->n_ssids)
+ next_delay = ieee80211_scan_passive_time(local);
+ else
ieee80211_scan_state_send_probe(local, &next_delay);
- next_delay = IEEE80211_CHANNEL_TIME;
- }

/* Now, just wait a bit and we are all done! */
ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
@@ -700,7 +720,7 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
*/
if (chan->flags & IEEE80211_CHAN_NO_IR ||
!local->scan_req->n_ssids) {
- *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
+ *next_delay = ieee80211_scan_passive_time(local);
local->next_scan_state = SCAN_DECISION;
return;
}
--
1.7.9.5


--
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