[PATCH] cfg80211: allow driver to signal noise level

[PATCH] cfg80211: allow driver to signal noise level

[Holger Schurig]

Allows a WLAN driver to signal current noise level:

# iw eth1 link
Connected to 00:13:19:80:da:30 (on eth1)
        SSID: SSID
        freq: 2437
        RX: 424 bytes (5 packets)
        TX: 0 bytes (0 packets)
        signal: -49 dBm
        noise: -93 dBm
        tx bitrate: 11.0 MBit/s

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>

---

NOTE: I didn't find out how to modify wext-compat.c so
that "iwconfig" would also display the noise.

--- linux-wl.orig/include/linux/nl80211.h
+++ linux-wl/include/linux/nl80211.h
@@ -871,6 +871,8 @@
  * @NL80211_STA_INFO_RX_PACKETS: total received packet (u32, from this station)
  * @NL80211_STA_INFO_TX_PACKETS: total transmitted packets (u32, to this
  *	station)
+ * @NL80211_STA_INFO_NOISE: noise level (u8, dBm) (used in station mode for
+ *	"iw link")
  */
 enum nl80211_sta_info {
 	__NL80211_STA_INFO_INVALID,
@@ -884,6 +886,7 @@
 	NL80211_STA_INFO_TX_BITRATE,
 	NL80211_STA_INFO_RX_PACKETS,
 	NL80211_STA_INFO_TX_PACKETS,
+	NL80211_STA_INFO_NOISE,
 
 	/* keep last */
 	__NL80211_STA_INFO_AFTER_LAST,
--- linux-wl.orig/include/net/cfg80211.h
+++ linux-wl/include/net/cfg80211.h
@@ -309,6 +309,7 @@
  *  (tx_bitrate, tx_bitrate_flags and tx_bitrate_mcs)
  * @STATION_INFO_RX_PACKETS: @rx_packets filled
  * @STATION_INFO_TX_PACKETS: @tx_packets filled
+ * @STATION_INFO_NOISE: @noise filled
  */
 enum station_info_flags {
 	STATION_INFO_INACTIVE_TIME	= 1<<0,
@@ -321,6 +322,7 @@
 	STATION_INFO_TX_BITRATE		= 1<<7,
 	STATION_INFO_RX_PACKETS		= 1<<8,
 	STATION_INFO_TX_PACKETS		= 1<<9,
+	STATION_INFO_NOISE		= 1<<10,
 };
 
 /**
@@ -367,6 +369,7 @@
  * @plid: mesh peer link id
  * @plink_state: mesh peer link state
  * @signal: signal strength of last received packet in dBm
+ * @noise: noise level in dBm
  * @txrate: current unicast bitrate to this station
  * @rx_packets: packets received from this station
  * @tx_packets: packets transmitted to this station
@@ -384,6 +387,7 @@
 	u16 plid;
 	u8 plink_state;
 	s8 signal;
+	s8 noise;
 	struct rate_info txrate;
 	u32 rx_packets;
 	u32 tx_packets;
--- linux-wl.orig/net/wireless/nl80211.c
+++ linux-wl/net/wireless/nl80211.c
@@ -1636,6 +1636,9 @@
 	if (sinfo->filled & STATION_INFO_SIGNAL)
 		NLA_PUT_U8(msg, NL80211_STA_INFO_SIGNAL,
 			   sinfo->signal);
+	if (sinfo->filled & STATION_INFO_NOISE)
+		NLA_PUT_U8(msg, NL80211_STA_INFO_NOISE,
+			   sinfo->noise);
 	if (sinfo->filled & STATION_INFO_TX_BITRATE) {
 		txrate = nla_nest_start(msg, NL80211_STA_INFO_TX_BITRATE);
 		if (!txrate)

-- 
http://www.holgerschurig.de

Re: [PATCH] cfg80211: allow driver to signal noise level

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 584 bytes --]

On Tue, 2009-10-20 at 14:13 +0200, Holger Schurig wrote:
> Allows a WLAN driver to signal current noise level:
> 
> # iw eth1 link
> Connected to 00:13:19:80:da:30 (on eth1)
>         SSID: SSID
>         freq: 2437
>         RX: 424 bytes (5 packets)
>         TX: 0 bytes (0 packets)
>         signal: -49 dBm
>         noise: -93 dBm
>         tx bitrate: 11.0 MBit/s
> 
> Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>

NACKed-by: Johannes Berg <johannes@sipsolutions.net>

As discussed previously, noise is not a property of a station.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 801 bytes --]

Re: [PATCH] cfg80211: allow driver to signal noise level

[Henning Rogge]

[-- Attachment #1: Type: text/plain, Size: 1268 bytes --]

Am Wed October 21 2009 01:18:11 schrieb Johannes Berg:
> On Tue, 2009-10-20 at 14:13 +0200, Holger Schurig wrote:
> > Allows a WLAN driver to signal current noise level:
> >
> > # iw eth1 link
> > Connected to 00:13:19:80:da:30 (on eth1)
> >         SSID: SSID
> >         freq: 2437
> >         RX: 424 bytes (5 packets)
> >         TX: 0 bytes (0 packets)
> >         signal: -49 dBm
> >         noise: -93 dBm
> >         tx bitrate: 11.0 MBit/s
> >
> > Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
>
> NACKed-by: Johannes Berg <johannes@sipsolutions.net>
>
> As discussed previously, noise is not a property of a station.
Noise it not a property of a link between two stations, but a property of the 
local station alone (the point where the noise was measured).

Do we have a netlink part to put in properties like this ?

Henning Rogge

-- 
Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
Kommunikation, Informationsverarbeitung und Ergonomie FKIE
Kommunikationssysteme (KOM)
Neuenahrer Straße 20, 53343 Wachtberg, Germany
Telefon +49 228 9435-263,   Fax +49 228 9435 685
mailto:henning.rogge@fkie.fraunhofer.de http://www.fkie.fraunhofer.de
GPG: E1C6 0914 490B 3909 D944 F80D 4487 C67C 55EC CFE0


[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 197 bytes --]

Re: [PATCH] cfg80211: allow driver to signal noise level

[Holger Schurig]

On Wednesday 21 October 2009 01:18:11 Johannes Berg wrote:
> As discussed previously, noise is not a property of a station.

URL?


Should I aim for an "iw dev XXX show noise", e.g. try to
handle it as a property of the card?  I could either add
an .get_noise() to cfg80211_ops, or better an .get_card_status()
with some bitmask of filled fields, like for the .get_station()
call. What would you prefer?

-- 
http://www.holgerschurig.de

Re: [PATCH] cfg80211: allow driver to signal noise level

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 718 bytes --]

On Thu, 2009-10-22 at 09:13 +0200, Holger Schurig wrote:
> On Wednesday 21 October 2009 01:18:11 Johannes Berg wrote:
> > As discussed previously, noise is not a property of a station.
> 
> URL?

At the wireless summit in Berlin, I think. I realise that not everybody
can be there, but still:
http://wireless.kernel.org/en/developers/Summits/Berlin-2009/notes

> 
> Should I aim for an "iw dev XXX show noise", e.g. try to
> handle it as a property of the card?  I could either add
> an .get_noise() to cfg80211_ops, or better an .get_card_status()
> with some bitmask of filled fields, like for the .get_station()
> call. What would you prefer?

It's really a property of the _channel_.

johannes

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 801 bytes --]

Re: [PATCH] cfg80211: allow driver to signal noise level

[Holger Schurig]

> It's really a property of the _channel_.

Please don't be so terse. That's not helpful. If you don't have 
time, then don't answer at all :-)


How would like to see an interface to get the noise out of the 
driver?



-- 
http://www.holgerschurig.de

Re: [PATCH] cfg80211: allow driver to signal noise level

[Bob Copeland]

On Tue, Oct 20, 2009 at 8:13 AM, Holger Schurig
<hs4233@mail.mn-solutions.de> wrote:
> Allows a WLAN driver to signal current noise level:
>

If the patch does survive in some form, can you change
the patch description to use "indicate" instead of
"signal?"  My internal parser kept searching for the
missing verb until I realized we were talking about
signalling the noise level instead of the signal [or]
noise level :)

-- 
Bob Copeland %% www.bobcopeland.com