From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:39523 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760727AbYFZUTL (ORCPT ); Thu, 26 Jun 2008 16:19:11 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1KBxvx-0006KC-MI for linux-wireless@vger.kernel.org; Thu, 26 Jun 2008 22:19:09 +0200 Subject: basic rate set / response frame rate From: Johannes Berg To: Linux Wireless Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-JxEWCrixOzwcolDn5GQl" Date: Thu, 26 Jun 2008 22:18:30 +0200 Message-Id: <1214511510.3783.44.camel@johannes.berg> (sfid-20080626_221917_390875_934D72E9) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-JxEWCrixOzwcolDn5GQl Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi, How does hardware currently handle the control response (ACK/CTS) frame rate? In 802.11 clause 9.6 talks about this, and we implement basic rate handling in mac80211 to calculate the control response duration, but we never tell drivers what bitrate to transmit control response frames at. I suspect this is broken in all drivers (except maybe iwlwifi which probably does it all in firmware.) The problem then is that if the AP has basic rates higher than your firmware/hardware default, the control response takes too long and the NAV isn't updated correctly in other STAs. How should we fix this? The most straight-forward way would be to include a map of rate -> basic rate into ieee80211_bss_conf, but that isn't easy because the size of the map isn't known. Another way would be to just give the driver the basic rate set, but that means it has to calculate the mapping itself, subject to all the rules in 802.11 clause 9.6. Therefore, I prefer the former way, or giving the driver a function to call for each rate=EF=BB=BF on bss_info_changed to calculate the mapping. johannes --=-JxEWCrixOzwcolDn5GQl Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJIY/mRAAoJEKVg1VMiehFYuI8P/RAjiQMrAMGYFQxxC75QQeDe IBtgCpmab0eMnfbvCcvYMh0NC/O/tsTiJDNgRm/nujXbLRQ/uYcknP1IVIB8S4i/ /nY3U1WfAriPh2wSL2LKZ2JvnkFZqpGdS0CIZI9gInrc/t0zFzFZgfgQaggY2Ge9 CM2Pkp7QBYovBA1M4RwUyAv/TdUbi0t1DOIafmfOyLqFlGC+nL5P1c/8luR1Qfpe A+g/y+Xfh0H5pz9UmN1gF9ryIrVAPu460ad7gVPTYGD4DMmsjTdmD9KTOxaXiDxT 1ZBD68BkYl6QnSoZDfGdWcLhZiBveanJLVC3MSZ3iDypaMKbFm5gVd8vQRjk8UpC qDWqcS8dYaaWcGC1AFTuArwCeNXod/FJV8Xa1OgdGiSXYAJIHsE9rbJv9VT/cBjy 6Qrud+49XhwV1RmsQ9NBpVd5d6tl/ccHCMZ5pcPYI6bsN59gikiUV0dhnq4cQUlm HL0Vqodqb4aoezoHEbwBWIdBPX02/8buo4BDbpoKsg/h40SpXp96Rw0kp/Qel7jE +xYKZakmBoG/r+2TFgkHdKUT7AwtKfcsGpBH0bVR3r1MhVU0ZGJqCSoNL1QGHgE+ z+nLl6kPSerSuolfXk9cAzEXxRQNErgfCeZxar4/Zw5Llvn2yGtWzgCHLIicAFFl RnvrUmUHhdoUH73LeOhA =wgQb -----END PGP SIGNATURE----- --=-JxEWCrixOzwcolDn5GQl--