Return-path: Received: from mta-1.ms.rz.RWTH-Aachen.DE ([134.130.7.72]:33081 "EHLO mta-1.ms.rz.rwth-aachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753605AbYDMIcD (ORCPT ); Sun, 13 Apr 2008 04:32:03 -0400 Received: from ironport-out-2.rz.rwth-aachen.de ([134.130.3.59]) by mta-1.ms.rz.RWTH-Aachen.de (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) with ESMTP id <0JZ9005P091C2BC0@mta-1.ms.rz.RWTH-Aachen.de> for linux-wireless@vger.kernel.org; Sun, 13 Apr 2008 10:32:00 +0200 (CEST) Date: Sun, 13 Apr 2008 10:31:59 +0200 From: =?UTF-8?B?VGhvbWFzIELDpGNobGVy?= Subject: Re: RaLink RT2500 802.11g Cardbus/mini-PCI In-reply-to: <1208074049.4111.18.camel@johannes.berg> To: Johannes Berg Cc: =?UTF-8?B?VGhvbWFzIELDpGNobGVy?= , Ivo van Doorn , linux-wireless@vger.kernel.org, "John W. Linville" , Vladimir Koutny Message-id: <4801C4FF.5060606@archlinux.org> (sfid-20080413_093212_722704_BD0F2438) MIME-version: 1.0 Content-type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary=------------enigCA4319B262AB72E5671FD8F0 References: <35856.201.36.161.238.1206999707.squirrel@mamao.cetuc.puc-rio.br> <200804021932.26046.IvDoorn@gmail.com> <47FE8FAD.9020802@archlinux.org> <200804121246.44236.IvDoorn@gmail.com> <4800F76C.7000801@archlinux.org> <1208072495.4111.10.camel@johannes.berg> <1208074049.4111.18.camel@johannes.berg> Sender: linux-wireless-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigCA4319B262AB72E5671FD8F0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Johannes Berg schrieb: >>> I compiled half a dozen kernels and now figured it out. This is the=20 >>> patch that causes rt2500pci to be slow. If I revert it, it is fast ag= ain: >>> http://git.kernel.org/?p=3Dlinux/kernel/git/torvalds/linux-2.6.git;a=3D= commitdiff;h=3Dd43c7b37ad787173d08683f05eadeea0398fefdf >=20 >> That's odd. But that patch looks a bit fishy now that I look at it, ca= re >> to try below change (manually, this isn't a patch)? >> >> johannes >> >> bool use_protection =3D (erp_value & WLAN_ERP_USE_PROTECTION) = !=3D 0; >> - bool use_short_preamble =3D (erp_value & WLAN_ERP_BARKER_PREAM= BLE) =3D=3D 0; >> =EF=BB=BF=EF=BB=BF+ bool use_short_preamble =3D (erp_value & WLA= N_ERP_BARKER_PREAMBLE) !=3D 0; >> DECLARE_MAC_BUF(mac); >=20 > No, wait, I'm confused, the original patch is correct. As far as I can > tell, the code there is correct. The bug in that code was actually > introduced by me based on the wrong thinking I just did again. I figured as much from the original commit message. So rt2500pci works=20 properly when the use_short_preamble has the wrong value, and breaks=20 when it has the right one. By the way, 2.6.25-rc8 was the first time that rt2500pci was ever fast=20 enough to be usable at all for me, so the bug you introduced seemed to=20 be the fix for my speed problems (which is odd). My guess is that=20 rt2500pci treats use_short_preamble wrong. --------------enigCA4319B262AB72E5671FD8F0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREIAAYFAkgBxP8ACgkQEda5KzHP/VBmEACggIeHQqoQ+4eQOHMuNx4lRKqM vYYAniLr0TIGGEDQPFh/Eb+2iG9RJKU3 =GGxl -----END PGP SIGNATURE----- --------------enigCA4319B262AB72E5671FD8F0--