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Date: Fri, 21 Jan 2011 10:03:08 -0800
From: greearb@...delatech.com
To: netdev@...r.kernel.org
Cc: Ben Greear <greearb@...delatech.com>
Subject: [PATCH v2] mac80211: Optimize scans on current operating channel.
From: Ben Greear <greearb@...delatech.com>
This should decrease un-necessary flushes, on/off channel work,
and channel changes in cases where the only scanned channel is
the current operating channel.
Signed-off-by: Ben Greear <greearb@...delatech.com>
---
v2: Check channels instead of flag when determining if we should
do a channel change in scan_completed_finish.
:100644 100644 c47d7c0... 59fe5e7... M net/mac80211/ieee80211_i.h
:100644 100644 1236710... e6de0e7... M net/mac80211/rx.c
:100644 100644 3e660db... fa0aeb9... M net/mac80211/scan.c
net/mac80211/ieee80211_i.h | 5 +++++
net/mac80211/rx.c | 11 ++++++++---
net/mac80211/scan.c | 41 +++++++++++++++++++++++++----------------
3 files changed, 38 insertions(+), 19 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c47d7c0..59fe5e7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -660,6 +660,10 @@ struct tpt_led_trigger {
* that the scan completed.
* @SCAN_ABORTED: Set for our scan work function when the driver reported
* a scan complete for an aborted scan.
+ * @SCAN_LEFT_OPER_CHANNEL: Set this flag if the scan process leaves the
+ * operating channel at any time. If scanning ONLY the current operating
+ * channel this flag should not be set, and this will allow fewer
+ * offchannel changes.
*/
enum {
SCAN_SW_SCANNING,
@@ -667,6 +671,7 @@ enum {
SCAN_OFF_CHANNEL,
SCAN_COMPLETED,
SCAN_ABORTED,
+ SCAN_LEFT_OPER_CHANNEL,
};
/**
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1236710..e6de0e7 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -388,6 +388,7 @@ ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
struct ieee80211_local *local = rx->local;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
struct sk_buff *skb = rx->skb;
+ int ret;
if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
return RX_CONTINUE;
@@ -396,10 +397,14 @@ ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
return ieee80211_scan_rx(rx->sdata, skb);
if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
- /* drop all the other packets during a software scan anyway */
- if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
+ ret = ieee80211_scan_rx(rx->sdata, skb);
+ /* drop all the other packets while scanning off channel */
+ if (ret != RX_QUEUED &&
+ test_bit(SCAN_OFF_CHANNEL, &local->scanning)) {
dev_kfree_skb(skb);
- return RX_QUEUED;
+ return RX_QUEUED;
+ }
+ return ret;
}
/* scanning finished during invoking of handlers */
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 3e660db..fa0aeb9 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -293,11 +293,14 @@ static void __ieee80211_scan_completed_finish(struct ieee80211_hw *hw,
{
struct ieee80211_local *local = hw_to_local(hw);
- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+ if ((local->oper_channel != local->hw.conf.channel) || was_hw_scan)
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+
if (!was_hw_scan) {
ieee80211_configure_filter(local);
drv_sw_scan_complete(local);
- ieee80211_offchannel_return(local, true);
+ if (test_bit(SCAN_LEFT_OPER_CHANNEL, &local->scanning))
+ ieee80211_offchannel_return(local, true);
}
mutex_lock(&local->mtx);
@@ -397,13 +400,10 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
drv_sw_scan_start(local);
- ieee80211_offchannel_stop_beaconing(local);
-
local->leave_oper_channel_time = 0;
local->next_scan_state = SCAN_DECISION;
local->scan_channel_idx = 0;
-
- drv_flush(local, false);
+ __clear_bit(SCAN_LEFT_OPER_CHANNEL, &local->scanning);
ieee80211_configure_filter(local);
@@ -543,7 +543,18 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
}
mutex_unlock(&local->iflist_mtx);
- if (local->scan_channel) {
+ next_chan = local->scan_req->channels[local->scan_channel_idx];
+
+ if (local->oper_channel == local->hw.conf.channel) {
+ if (next_chan == local->oper_channel)
+ local->next_scan_state = SCAN_SET_CHANNEL;
+ else
+ /*
+ * we're on the operating channel currently, let's
+ * leave that channel now to scan another one
+ */
+ local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
+ } else {
/*
* we're currently scanning a different channel, let's
* see if we can scan another channel without interfering
@@ -559,7 +570,6 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
*
* Otherwise switch back to the operating channel.
*/
- next_chan = local->scan_req->channels[local->scan_channel_idx];
bad_latency = time_after(jiffies +
ieee80211_scan_get_channel_time(next_chan),
@@ -577,12 +587,6 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
else
local->next_scan_state = SCAN_SET_CHANNEL;
- } else {
- /*
- * we're on the operating channel currently, let's
- * leave that channel now to scan another one
- */
- local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
}
*next_delay = 0;
@@ -591,9 +595,12 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
unsigned long *next_delay)
{
+ ieee80211_offchannel_stop_beaconing(local);
+
ieee80211_offchannel_stop_station(local);
__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
+ __set_bit(SCAN_LEFT_OPER_CHANNEL, &local->scanning);
/*
* What if the nullfunc frames didn't arrive?
@@ -640,8 +647,10 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
chan = local->scan_req->channels[local->scan_channel_idx];
local->scan_channel = chan;
- if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
- skip = 1;
+
+ if (chan != local->hw.conf.channel)
+ if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
+ skip = 1;
/* advance state machine to next channel/band */
local->scan_channel_idx++;
--
1.7.2.3
--
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