From cd2bb512cda58f1efb922ad6dc29013ea5d5d9d0 Mon Sep 17 00:00:00 2001 From: Sam Leffler Date: Thu, 11 Oct 2012 21:03:35 -0700 Subject: [PATCH] mac80211: add support for tx to abort low priority scan requests 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 Signed-off-by: Amitkumar Karwar Signed-off-by: Bing Zhao [set feature flag only if software scan is used] Signed-off-by: Johannes Berg --- net/mac80211/ieee80211_i.h | 2 ++ net/mac80211/main.c | 3 +++ net/mac80211/scan.c | 21 +++++++++++++++++---- 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 6327816790e6..02e47930964f 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 931f14f3281f..ba5a23249771 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -602,6 +602,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len, NL80211_FEATURE_SAE | NL80211_FEATURE_HT_IBSS; + if (!ops->hw_scan) + wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN; + if (!ops->set_key) wiphy->flags |= WIPHY_FLAG_IBSS_RSN; diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 987c75d46bc0..13d23299e696 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);