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* [mac80211] UAPSD: WLAN_STA_PS flag  cleared prematurely?
@ 2012-03-16  9:26 Marco Porsch
  2012-03-16 12:44 ` Johannes Berg
  0 siblings, 1 reply; 6+ messages in thread
From: Marco Porsch @ 2012-03-16  9:26 UTC (permalink / raw)
  To: johannes; +Cc: linux-wireless

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?

Regards,
Marco

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [mac80211] UAPSD: WLAN_STA_PS flag  cleared prematurely?
  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
  0 siblings, 1 reply; 6+ messages in thread
From: Johannes Berg @ 2012-03-16 12:44 UTC (permalink / raw)
  To: Marco Porsch; +Cc: linux-wireless

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?

johannes


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [mac80211] UAPSD: WLAN_STA_PS flag  cleared prematurely?
  2012-03-16 12:44 ` Johannes Berg
@ 2012-03-16 13:38   ` Marco Porsch
  2012-03-16 13:40     ` Johannes Berg
  0 siblings, 1 reply; 6+ messages in thread
From: Marco Porsch @ 2012-03-16 13:38 UTC (permalink / raw)
  To: Johannes Berg; +Cc: linux-wireless

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?
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);
	}
}

Open issues:
Which tid?
Would this Null now be sent after or before the last frame?
What if the EOSP frame is lost?

Regards,
Marco


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [mac80211] UAPSD: WLAN_STA_PS flag  cleared prematurely?
  2012-03-16 13:38   ` Marco Porsch
@ 2012-03-16 13:40     ` Johannes Berg
  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
  0 siblings, 2 replies; 6+ messages in thread
From: Johannes Berg @ 2012-03-16 13:40 UTC (permalink / raw)
  To: Marco Porsch; +Cc: linux-wireless

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


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [mac80211] UAPSD: WLAN_STA_PS flag  cleared prematurely?
  2012-03-16 13:40     ` Johannes Berg
@ 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
  1 sibling, 0 replies; 6+ messages in thread
From: Marco Porsch @ 2012-03-16 13:58 UTC (permalink / raw)
  To: Johannes Berg; +Cc: linux-wireless


[-- Attachment #1.1: Type: text/plain, Size: 2248 bytes --]

On 03/16/12 14:40, Johannes Berg wrote:
> 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;
> }

Oh, yes, I see. In case of reason==IEEE80211_FRAME_RELEASE_PSPOLL, it is 
intended to not send the EOSP, but still set IEEE80211_TX_STATUS_EOSP.

Who sends the patch?

Regards,
Marco

[-- Attachment #1.2: marco_porsch.vcf --]
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fn:Marco Porsch
n:Porsch;Marco
org:Chemnitz University of Technology;Communication Networks
adr;quoted-printable;quoted-printable:Fakult=C3=A4t f=C3=BCr Elektrotechnik und Informationstechnik , Professur=
	 Kommunikationsnetze;;Technische Universit=C3=A4t Chemnitz;Chemnitz;;D - 09107;Germany
email;internet:marco.porsch@etit.tu-chemnitz.de
title:Dipl.-Ing.
tel;work:+49 371 531 37523
version:2.1
end:vcard


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^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH] mac80211: end service period only after sending last buffered frame
  2012-03-16 13:40     ` Johannes Berg
  2012-03-16 13:58       ` Marco Porsch
@ 2012-03-16 14:30       ` Marco Porsch
  1 sibling, 0 replies; 6+ messages in thread
From: Marco Porsch @ 2012-03-16 14:30 UTC (permalink / raw)
  To: johannes; +Cc: linux-wireless, Marco Porsch


Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
---
 net/mac80211/sta_info.c |   16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f468eb1..9b63cd7 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1257,13 +1257,15 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta,
 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
 				qoshdr = ieee80211_get_qos_ctl(hdr);
 
-			/* 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;
+			/* end service period after last 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;
+			}
 
 			if (qoshdr)
 				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-03-16 14:30 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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
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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