2019-10-30 21:34:05

by Ahmed Zaki

Subject: [PATCH 1/1] sta_info: fix insane values in iw sta dump "inactive time"

In the first 5 mins after boot (initial jiffies),
ieee80211_sta_last_active() returns zero in case last_ack is zero. This
leads to insane values appearing in "inactive time".

Fix by returning last_rx if last_ack == 0.
---
net/mac80211/sta_info.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bd11fef2139f..428866ff7c0a 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2457,7 +2457,8 @@ unsigned long ieee80211_sta_last_active(struct sta_info *sta)
{
struct ieee80211_sta_rx_stats *stats = sta_get_last_rx_stats(sta);

- if (time_after(stats->last_rx, sta->status_stats.last_ack))
+ if (!sta->status_stats.last_ack ||
+ time_after(stats->last_rx, sta->status_stats.last_ack))
return stats->last_rx;
return sta->status_stats.last_ack;
}
--
2.17.1

2019-10-31 08:13:30

by Johannes Berg

Subject: Re: [PATCH 1/1] sta_info: fix insane values in iw sta dump "inactive time"

On Wed, 2019-10-30 at 15:31 -0600, Ahmed Zaki wrote:
> In the first 5 mins after boot (initial jiffies),
> ieee80211_sta_last_active() returns zero in case last_ack is zero. This
> leads to insane values appearing in "inactive time".
>
> Fix by returning last_rx if last_ack == 0.

Please read

https://wireless.wiki.kernel.org/en/developers/Documentation/SubmittingPatches

johannes