From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ew0-f220.google.com ([209.85.219.220]:42978 "EHLO mail-ew0-f220.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758466Ab0DWSI6 (ORCPT ); Fri, 23 Apr 2010 14:08:58 -0400 Received: by ewy20 with SMTP id 20so3164263ewy.1 for ; Fri, 23 Apr 2010 11:08:57 -0700 (PDT) From: Ivo van Doorn To: Gertjan van Wingerde Subject: Re: [PATCH] rt2x00: rt2800lib: disable HT40 for now as it causes reception problems Date: Fri, 23 Apr 2010 20:08:54 +0200 Cc: Helmut Schaa , John Linville , linux-wireless@vger.kernel.org, rt2x00 Users List References: <201004231505.29689.helmut.schaa@googlemail.com> <4BD1BAF8.1060908@gmail.com> In-Reply-To: <4BD1BAF8.1060908@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <201004232008.55022.IvDoorn@gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Friday 23 April 2010, Gertjan van Wingerde wrote: > On 04/23/10 15:05, Helmut Schaa wrote: > > Disable HT40 support for now as it causes rx problems with HT40 capable > > 11n APs (when mac80211 enables HT40, rx is completely disfunctional). > > > > Once the rt2800 HT code is capable of using HT40 we should enable the > > flag again. > > > > I only tested this patch with a rt305x SoC device, nevertheless the > > patch disables HT40 also on PCI and USB rt2800 devices. > > > > Signed-off-by: Helmut Schaa > > I can confirm that this also helps for PCI and USB devices. > With this patch applied all my rt28xx and rt30xx based devices starting working correctly. > > So, definately, > > Acked-by: Gertjan van Wingerde And also thanks for figuring this out, this at least gives a good starting point for investigation for resolving the last issues. :) Acked-by: Ivo van Doorn > > --- > > > > Using this patch I was able to associate a rt305x SoC device with my 11n > > capable AP using WPA and the connection basically works although I see lots > > of retried frames when sniffing the wireless traffic. > > > > If someone already had success with rt2800 and HT40 capable APs we should > > consider to only conditionally unset the HT40 flag for 305x SoC devices. > > > > drivers/net/wireless/rt2x00/rt2800lib.c | 5 ++++- > > 1 files changed, 4 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c > > index 2648f31..aa02ff6 100644 > > --- a/drivers/net/wireless/rt2x00/rt2800lib.c > > +++ b/drivers/net/wireless/rt2x00/rt2800lib.c > > @@ -2318,8 +2318,11 @@ int rt2800_probe_hw_mode(struct rt2x00_dev *rt2x00dev) > > else > > spec->ht.ht_supported = false; > > > > + /* > > + * Don't set IEEE80211_HT_CAP_SUP_WIDTH_20_40 for now as it causes > > + * reception problems with HT40 capable 11n APs > > + */ > > spec->ht.cap = > > - IEEE80211_HT_CAP_SUP_WIDTH_20_40 | > > IEEE80211_HT_CAP_GRN_FLD | > > IEEE80211_HT_CAP_SGI_20 | > > IEEE80211_HT_CAP_SGI_40 | > >