Re: [PATCH] mac80211: Don't buffer non-bufferable MMPDUs

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2016-01-05 at 16:43 +0100, Helmut Schaa wrote:

> > That said, it obviously also points to a driver bug not treating
> > these frames correctly, so you might want to investigate why you
> > got here to start with!
> 
> It was not the driver marking the frame as filtered but mac80211
> itself in status.c:
> 
>                 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
>                 if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
>                         /*
>                          * The STA is in power save mode, so assume
>                          * that this TX packet failed because of
> that.
>                          */
>                         ieee80211_handle_filtered_frame(local, sta,
> skb);
>                         rcu_read_unlock();
>                         return;
>                 }

Ah, yes, ok. So the frame simply didn't go through, for whatever
reason. Hopefully the driver actually transmitted it :)

> However, I've put the code into ieee80211_handle_filtered_frame to
> not grow ieee80211_tx_status even more :)
>
> If you prefer to add it here directly I'm fine to change it.
> 

No, looks fine as is. I just misunderstood how we got here.

johannes