From: Johannes Berg <johannes@sipsolutions.net>
To: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
Cc: linux-wireless@vger.kernel.org
Subject: Re: [mac80211] UAPSD: WLAN_STA_PS flag cleared prematurely?
Date: Fri, 16 Mar 2012 14:40:40 +0100 [thread overview]
Message-ID: <1331905240.6753.14.camel@jlt3.sipsolutions.net> (raw)
In-Reply-To: <4F634259.7040107@etit.tu-chemnitz.de>
On Fri, 2012-03-16 at 14:38 +0100, Marco Porsch wrote:
> On 03/16/12 13:44, Johannes Berg wrote:
> > On Fri, 2012-03-16 at 10:26 +0100, Marco Porsch wrote:
> >> Hi all,
> >>
> >> in sta_info.c : ieee80211_sta_ps_deliver_response the
> >> IEEE80211_TX_STATUS_EOSP is set for all to-be-sent frames, not only for
> >> the last. But only the last buffered frame actually gets the EOSP flag.
> >>
> >>
> >> /* set EOSP for the frame */
> >> if (reason == IEEE80211_FRAME_RELEASE_UAPSD&&
> >> qoshdr&& skb_queue_empty(&frames))
> >> *qoshdr |= IEEE80211_QOS_CTL_EOSP;
> >>
> >> info->flags |= IEEE80211_TX_STATUS_EOSP |
> >> IEEE80211_TX_CTL_REQ_TX_STATUS;
> >>
> >>
> >> Consequence is, that the WLAN_STA_SP flag gets cleared (multiple times)
> >> in ieee80211_tx_status before the last frame with EOSP has been sent.
> >> Is this correct?
> >
> > Looks like the bug is above, the EOSP/TX_STATUS should only be set for
> > the last frame?
>
> I Agree. But what about the case, when the last frame is not a QoS
> frame? Can this even happen - or is U-APSD only for QoS STA?
uAPSD can only be used by a QoS STA.
> Then we would have to manually append a QoS Null with the EOSP flag +
> TX_STATUS?
>
> So like this:
>
> /* set EOSP for the _last_ frame or appended a QoS Null when needed */
> if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
> skb_queue_empty(&frames)) {
> if (qoshdr) {
> *qoshdr |= IEEE80211_QOS_CTL_EOSP;
>
> info->flags |= IEEE80211_TX_STATUS_EOSP |
> IEEE80211_TX_CTL_REQ_TX_STATUS;
> } else {
> ieee80211_send_null_response(sdata, tid, reason);
> }
> }
No, I think it should be more like this:
/* set EOSP for the frame */
if (skb_queue_empty(&frames)) {
if (reason == IEEE80211_FRAME_RELEASE_UAPSD && qoshdr)
*qoshdr |= IEEE80211_QOS_CTL_EOSP;
info->flags |= IEEE80211_TX_STATUS_EOSP |
IEEE80211_TX_CTL_REQ_TX_STATUS;
}
johannes
next prev parent reply other threads:[~2012-03-16 13:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-16 9:26 [mac80211] UAPSD: WLAN_STA_PS flag cleared prematurely? Marco Porsch
2012-03-16 12:44 ` Johannes Berg
2012-03-16 13:38 ` Marco Porsch
2012-03-16 13:40 ` Johannes Berg [this message]
2012-03-16 13:58 ` Marco Porsch
2012-03-16 14:30 ` [PATCH] mac80211: end service period only after sending last buffered frame Marco Porsch
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