mac80211: implement packet loss notification

For drivers that have accurate TX status reporting
we can report the number of consecutive lost packets
to userspace using the new cfg80211 CQM event. The
threshold is fixed right now, this may need to be
improved in the future.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2010-11-24 08:10:06 +01:00 committed by John W. Linville
parent c063dbf52b
commit 99ba2a1428
2 changed files with 25 additions and 0 deletions

View File

@ -248,6 +248,7 @@ enum plink_state {
* @sta: station information we share with the driver
* @dead: set to true when sta is unlinked
* @uploaded: set to true when sta is uploaded to the driver
* @lost_packets: number of consecutive lost packets
*/
struct sta_info {
/* General information, mostly static */
@ -335,6 +336,8 @@ struct sta_info {
} debugfs;
#endif
unsigned int lost_packets;
/* keep last! */
struct ieee80211_sta sta;
};

View File

@ -161,6 +161,15 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
ieee80211_sta_tx_notify(sdata, (void *) skb->data);
}
/*
* Use a static threshold for now, best value to be determined
* by testing ...
* Should it depend on:
* - on # of retransmissions
* - current throughput (higher value for higher tpt)?
*/
#define STA_LOST_PKT_THRESHOLD 50
void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
{
struct sk_buff *skb2;
@ -247,6 +256,19 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
if (!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
(info->flags & IEEE80211_TX_STAT_ACK))
ieee80211_frame_acked(sta, skb);
if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
if (info->flags & IEEE80211_TX_STAT_ACK) {
if (sta->lost_packets)
sta->lost_packets = 0;
} else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
cfg80211_cqm_pktloss_notify(sta->sdata->dev,
sta->sta.addr,
sta->lost_packets,
GFP_ATOMIC);
sta->lost_packets = 0;
}
}
}
rcu_read_unlock();