Return-path: Received: from mail-gw0-f46.google.com ([74.125.83.46]:43589 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754037Ab1DGWEw (ORCPT ); Thu, 7 Apr 2011 18:04:52 -0400 Received: by gwaa18 with SMTP id a18so1024405gwa.19 for ; Thu, 07 Apr 2011 15:04:51 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4D8EB693.5010704@users.sourceforge.net> References: <813132.20275.qm@web29506.mail.ird.yahoo.com> <20110318085401.GB2162@redhat.com> <4D8EB693.5010704@users.sourceforge.net> Date: Thu, 7 Apr 2011 23:04:51 +0100 Message-ID: Subject: Re: rtl8187b throughput-related regression in 2.6.35.x fixed in 2.6.37.x From: Hin-Tak Leung To: Hin-Tak Leung Cc: Stanislaw Gruszka , Larry Finger , herton@mandriva.com.br, "John W. Linville" , linux-wireless@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sun, Mar 27, 2011 at 5:01 AM, Hin-Tak Leung wrote: > Stanislaw Gruszka wrote: >> >> On Fri, Mar 18, 2011 at 05:18:25AM +0000, Hin-Tak Leung wrote: >>> >>> Hi Larry/Herton/John, >>> >>> There appears to be some kind of throughput related regression in >>> 2.6.35.x (11-85-ish fedora, current long-term maintainance kernel) which is >>> fixed by putting compat-wireless 2.6.37.x (4) on. I just thought I should >>> mention this, in case somebody files a bug about rtl8187(b) being too slow, >>> that putting compat-wireless on might help. >>> >>> My AP machine was out for almost a year so I have not been using my >>> rtl8187b for a while. When I finally got that fixed, after a while I noticed >>> the throughput between the two machines was low (60KB/s, or 0.5Mb/s, >>> although iwconfig says rate=11Mb/s, etc). Putting compat-wireless on gets me >>> back the throughput I expect from a year ago (400KB/s+ onwards, or a few >>> Mb/s at least). So 2.6.31.x a year ago was okay, 2.6.37.x is okay, but there >>> appear to be something not quite right with 2.6.35.x in the middle. There >>> are too many changes, and it is probably not important since current-ish >>> kernel head is okay. >> >> Would be nice to have this fixed in stable. >> >> We have already one AP mode bug opened: >> http://bugzilla.redhat.com/show_bug.cgi?id=671514 >> >> It was recognized that this patch is needed in .35.11 (.35.9 is ok): >> http://git.kernel.org/linus/09a02fdb919876c01e8f05960750a418b3f7fa48 >> >> Not sure if this is the same issue, but perhaps you could try above >> patch. If it does not help, could you check if problem is >> 2.6.35.x -> 2.6.35.11 regression? >> >> Stanislaw >> > > Just checked again, downloading and using a bunch of compat tar balls. It > appeared that the throughput problem I reported above was fixed between > 2.6.37.4 and 2.6.38-rc7. In any case, it does not appear to be the ones you > mentioned. > > I might spend a bit more time eventually to see what fixes it. The one thing > interesting > about those two versions were Herton's house-keeping > > rtl8187: restore anaparam registers after reset with 8187B > rtl8187: fix wrong register initialization in 8187B > > and Thadeu Lima de Souza Cascardo > rtl8187b: do not do per packet TX AGC > > And the Signal level did seem to change from about -40 dBm to -30 > > But these are a bit curious how I did get good throughput with 2.6.31.x-ish Down to between: compat-wireless-2.6.37-4-sn.tar.bz2 compat-wireless-2.6.38-rc3-3.tar.bz2 compat-wireless-2.6.38-rc3-2.tar.bz2 doesn't build.