Return-path: Received: from mailguard.fgan.de ([128.7.3.5]:48178 "EHLO mailguard.fgan.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754517AbYLDJtC (ORCPT ); Thu, 4 Dec 2008 04:49:02 -0500 From: Henning Rogge To: Johannes Berg Subject: Re: RFC Patch v2: Add signal strength to nl80211station info Date: Thu, 4 Dec 2008 10:48:48 +0100 Cc: "Luis R. Rodriguez" , Henning Rogge , Luis Rodriguez , Marcel Holtmann , "linux-wireless" , "nbd@openwrt.org" References: <200811252131.30161.hrogge@googlemail.com> <200812031131.34936.rogge@fgan.de> <1228380472.3197.5.camel@Friederike-PC.hoffi> In-Reply-To: <1228380472.3197.5.camel@Friederike-PC.hoffi> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2154070.qjI3HfYJOV"; protocol="application/pgp-signature"; micalg=pgp-sha1 Message-Id: <200812041048.56327.rogge@fgan.de> (sfid-20081204_104929_597517_2DB6AD52) Sender: linux-wireless-owner@vger.kernel.org List-ID: --nextPart2154070.qjI3HfYJOV Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Am Thursday 04 December 2008 09:47:52 schrieb Johannes Berg: > On Wed, 2008-12-03 at 11:31 +0100, Henning Rogge wrote: > > What do you think about the idea to export the 802.11n transmission rate > > through the old WExt interface, so iwconfig will show the correct rate > > too ? But for this the "mcs to bitrate" tables would have to be moved to > > some other file, so wext.c can access them too (which one ?). > > No, that can't possibly work right, sorry. I think it would work for reading the bitrate with WExt, but not for settin= g=20 the bitrate. > > + * @NL80211_STA_INFO_SIGNAL: signal strength of last received package > > (u8, dBm) > > s8? should be signed, no? Yes, it should be signed, but nl80211 does not support signed values. Shall= I=20 document it as signed but use the unsigned macros to transmit it through=20 nl80211 to userspace (not sure about it) ? > > + * @NL80211_STA_INFO_RX_BITRATE: bitrate of last received unicast pack= et > > + * (u16, 100 kbit/s) > > I don't really like this. I know we cannot report the real information > yet because we don't even have the driver/mac80211 api but let's add rx > rate reporting when we have the HT information too. I'm not sure I understand your problem. We have the mcs number from the driver, we have the the 20/40 Mhz flag and = we=20 have to 400/800ns guard interval flag. That should be everything we need. > > + * @NL80211_STA_INFO_TX_BITRATE: current unicast tx rate (u16, 100 > > kbit/s) + * @NL80211_STA_INFO_TX_BITRATE_40_MHZ: dual channel > > transmission (flag) + * @NL80211_STA_INFO_TX_BITRATE_MCS: 802.11n MCS > > index of tx rate (u8) + * @NL80211_STA_INFO_TX_BITRATE_SHORT_GI: 802.11n > > with 400ns GI, 800ns + * otherwise, should be ignored if TX_BITRATE_MCS > > is not set (flag) > > I'm not sure I like the bitrate being used as prefix and final name, can > we have maybe TXRATE_ as prefix and use TXRATE_RATE, TXRATE_40, ...? Like this ? NL80211_STA_INFO_TXRATE_RATE NL80211_STA_INFO_TXRATE_40_MHZ NL80211_STA_INFO_TXRATE_MCS NL80211_STA_INFO_TXRATE_SHORT_GI > > +/* bitrate of 802.11n ht20 connections with 800ns guard interval in > > 100kbit/s */ > > +const u16 ieee80211n_ht20_gi800[] =3D { > > + 65, 130, 195, 260, 390, 520, 585, 650, > > + 130, 260, 390, 520, 780, 1040, 1170, 1300, > > + 195, 390, 585, 780, 1170, 1560, 1755, 1950, > > + 260, 520, 780, 1040, 1560, 2080, 2340, 2600 > > +}; > > + > > +/* bitrate of 802.11n ht20 connections with 400ns guard interval > > + * in 100kbit/s per spatial stream */ > > +const u16 ieee80211n_ht20_gi400[] =3D { > > + 72, 144, 217, 289, 433, 578, 650, 722, > > + 144, 289, 433, 578, 867, 1156, 1300, 1440, > > + 217, 433, 650, 867, 1300, 1733, 1950, 2167, > > + 289, 578, 867, 1157, 1733, 2311, 2600, 2889 > > +}; > > + > > +/* bitrate of 802.11n ht40 connections with 800ns guard interval > > + * in 100kbit/s per spatial stream */ > > +const u16 ieee80211n_ht40_gi800[] =3D { > > + 135, 270, 405, 540, 810, 1080, 1215, 1350, > > + 270, 540, 810, 1080, 1620, 2160, 2430, 2700, > > + 405, 810, 1215, 1620, 2430, 3240, 3645, 4050, > > + 540, 1080, 1620, 2160, 3240, 4320, 4860, 5400 > > +}; > > + > > +/* bitrate of 802.11n ht40 connections with 400ns guard interval > > + * in 100kbit/s per spatial stream */ > > +const u16 ieee80211n_ht40_gi400[] =3D { > > + 150, 300, 450, 600, 900, 1200, 1350, 1500, > > + 300, 600, 900, 1200, 1800, 2400, 2700, 3000, > > + 450, 900, 1350, 1800, 2700, 3600, 4050, 4500, > > + 600, 1200, 1800, 2400, 3600, 4800, 5400, 6000 > > +}; > > I definitely don't like this, ick, please put that into userspace. Is there some kind of userspace library I could put this function into ? Every userspace programm using nl80211 will need this translation function,= so=20 it would be bad to put it into the iw command. > > + sinfo->rx_bitrate =3D sta->last_rxrate_unicast; > > + > > + sinfo->tx_bitrate_flags =3D sta->last_tx_rate.flags & > > + (IEEE80211_TX_RC_MCS | > > + IEEE80211_TX_RC_40_MHZ_WIDTH | > > + IEEE80211_TX_RC_SHORT_GI); > > That looks very odd. Are you sure it's using the same rate flags? And if > it is, that's wrong, because cfg80211 must not rely on mac80211 flags. I just store them in the flags field and translate them into NL80211 flags= =20 later. They never leave the kernel. But I can add a new enum for this. Maybe this way ? enum station_info_txrate_flags { STATION_INFO_TXFLAGS_MCS, STATION_INFO_TXFLAGS_40_MHZ, STATION_INFO_TXFLAGS_SHORT_GI }; > > + if (!(sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)) { > > + struct ieee80211_supported_band *sband; > > + sband =3D > > sta->local->hw.wiphy->bands[sta->local->hw.conf.channel->band]; > > + sinfo->tx_bitrate =3D sband->bitrates[sta->last_tx_rate.idx].bitrate; > > + sinfo->tx_bitrate_mcs =3D 0; > I don't think you should initialise mcs here. I didn't liked to keep it uninitialized, but I can just delete the line. > Some places also need work on the coding style. Maybe you can give me an example, I'm still trying to learn the coding styl= e=20 for this group. Henning ************************************************* Diplom Informatiker Henning Rogge =46orschungsgesellschaft f=FCr Angewandte Naturwissenschaften e. V. (FGAN)=20 Neuenahrer Str. 20, 53343 Wachtberg, Germany Tel.: 0049 (0)228 9435-961 =46ax: 0049 (0)228 9435-685 E-Mail: rogge@fgan.de Web: www.fgan.de ************************************************ Sitz der Gesellschaft: Bonn Registergericht: Amtsgericht Bonn VR 2530 Vorstand: Dr. rer. nat. Ralf Dornhaus (Vors.), Prof. Dr. Joachim Ender=20 (Stellv.) --nextPart2154070.qjI3HfYJOV Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkk3p4EACgkQRIfGfFXsz+D1PwCfbXqlDiKz+dSTXLLQ9NIMfBbK tWUAnjXG0E9wR4lHZCI/2wP0OUl7hGk7 =iSTF -----END PGP SIGNATURE----- --nextPart2154070.qjI3HfYJOV--