[RFC] mac80211: reset connection poll on receiving unicast data frames

[RFC] mac80211: reset connection poll on receiving unicast data frames

[Rajkumar Manoharan]

In noisy channel conditions, some APs do not reply to probe
requests which results in STA disconnection. It is perfectly
fine to reset the connection polling if unicast frames are
received from that AP properly.

The reason behind to reset connection poll on unicast data
frames alone is that to preserve the PS recalculation on receiving
probe response.

This disconnection issue was reported with some buggy APs in noisy
environment, with the devices that does not support
IEEE80211_HW_REPORTS_TX_ACK_STATUS and running heavy downlink
unicast traffic from DS to STA. The probe response that was not
seen for the request sent followed by scan completion.

Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
---
 net/mac80211/mlme.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 45fbb9e..03d6cfc 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -141,6 +141,7 @@ void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata)
 		  round_jiffies_up(jiffies + IEEE80211_CONNECTION_IDLE_TIME));
 
 	ifmgd->probe_send_count = 0;
+	ifmgd->flags &= ~IEEE80211_STA_CONNECTION_POLL;
 }
 
 static int ecw2cw(int ecw)
@@ -1033,7 +1034,8 @@ void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
 	if (is_multicast_ether_addr(hdr->addr1))
 		return;
 
-	ieee80211_sta_reset_conn_monitor(sdata);
+	if (ieee80211_is_data(hdr->frame_control))
+		ieee80211_sta_reset_conn_monitor(sdata);
 }
 
 static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
-- 
1.7.3.5

Re: [RFC] mac80211: reset connection poll on receiving unicast data frames

[Johannes Berg]

On Tue, 2011-01-18 at 19:14 +0530, Rajkumar Manoharan wrote:
> In noisy channel conditions, some APs do not reply to probe
> requests which results in STA disconnection. It is perfectly
> fine to reset the connection polling if unicast frames are
> received from that AP properly.

I'm not convinced. We often have no trouble hearing the AP but the AP
isn't hearing us because sensitivity is different etc.

johannes

Re: [RFC] mac80211: reset connection poll on receiving unicast data frames

[Rajkumar Manoharan]

On Tue, Jan 18, 2011 at 07:21:20PM +0530, Johannes Berg wrote:
> On Tue, 2011-01-18 at 19:14 +0530, Rajkumar Manoharan wrote:
> > In noisy channel conditions, some APs do not reply to probe
> > requests which results in STA disconnection. It is perfectly
> > fine to reset the connection polling if unicast frames are
> > received from that AP properly.
> 
> I'm not convinced. We often have no trouble hearing the AP but the AP
> isn't hearing us because sensitivity is different etc.
>
But it does affect data transmission. STA is continuously receiving
data from AP. So we can ensure that connection is still alive
based on unicast frame though STA is not hearing probe response.

--
Rajkumar