From: Sam Leffler <sleffler@xxxxxxxxxxxx>
Use NL80211_SCAN_FLAG_LOW_PRIORITY flag in mac80211's scan state
machine to prematurely terminate scan operations if outbound
traffic collides. This is useful for marking background scans so
they don't affect throughput.
Signed-off-by: Sam Leffler <sleffler@xxxxxxxxxxxx>
Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
---
v3: Removed use of unlikely() macro (Johannes Berg)
Advertise low priority scan capability (Johannes Berg)
net/mac80211/ieee80211_i.h | 2 ++
net/mac80211/main.c | 3 ++-
net/mac80211/scan.c | 21 +++++++++++++++++----
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1fd7dfc..8c68877 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -866,6 +866,7 @@ enum {
* @SCAN_SUSPEND: Suspend the scan and go back to operating channel to
* send out data
* @SCAN_RESUME: Resume the scan and scan the next channel
+ * @SCAN_ABORT: Abort the scan and go back to operating channel
*/
enum mac80211_scan_state {
SCAN_DECISION,
@@ -873,6 +874,7 @@ enum mac80211_scan_state {
SCAN_SEND_PROBE,
SCAN_SUSPEND,
SCAN_RESUME,
+ SCAN_ABORT,
};
struct ieee80211_local {
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 473b755..da7e007 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -593,7 +593,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
WIPHY_FLAG_4ADDR_AP |
WIPHY_FLAG_4ADDR_STATION |
WIPHY_FLAG_REPORTS_OBSS |
- WIPHY_FLAG_OFFCHAN_TX;
+ WIPHY_FLAG_OFFCHAN_TX |
+ WIPHY_FLAG_LOW_PRIORITY_SCAN;
if (ops->remain_on_channel)
wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 5671fe5..8c41c91 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -466,6 +466,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
sizeof(*local->hw_scan_req) +
req->n_channels * sizeof(req->channels[0]);
local->hw_scan_req->ie = ies;
+ local->hw_scan_req->flags = req->flags;
local->hw_scan_band = 0;
@@ -566,6 +567,7 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
unsigned long min_beacon_int = 0;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_channel *next_chan;
+ enum mac80211_scan_state next_scan_state;
/*
* check if at least one STA interface is associated,
@@ -624,10 +626,18 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
usecs_to_jiffies(min_beacon_int * 1024) *
local->hw.conf.listen_interval);
- if (associated && (!tx_empty || bad_latency || listen_int_exceeded))
- local->next_scan_state = SCAN_SUSPEND;
- else
- local->next_scan_state = SCAN_SET_CHANNEL;
+ if (associated && !tx_empty) {
+ if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
+ next_scan_state = SCAN_ABORT;
+ else
+ next_scan_state = SCAN_SUSPEND;
+ } else if (associated && (bad_latency || listen_int_exceeded)) {
+ next_scan_state = SCAN_SUSPEND;
+ } else {
+ next_scan_state = SCAN_SET_CHANNEL;
+ }
+
+ local->next_scan_state = next_scan_state;
*next_delay = 0;
}
@@ -798,6 +808,9 @@ void ieee80211_scan_work(struct work_struct *work)
case SCAN_RESUME:
ieee80211_scan_state_resume(local, &next_delay);
break;
+ case SCAN_ABORT:
+ aborted = true;
+ goto out_complete;
}
} while (next_delay == 0);
--
1.7.0.4
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