Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:44026 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753325Ab1GWTWg (ORCPT ); Sat, 23 Jul 2011 15:22:36 -0400 Received: by vws1 with SMTP id 1so2276011vws.19 for ; Sat, 23 Jul 2011 12:22:36 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <201107151622.43671.chunkeey@googlemail.com> References: <201107151622.43671.chunkeey@googlemail.com> Date: Sat, 23 Jul 2011 14:22:35 -0500 Message-ID: (sfid-20110723_212240_076892_F67C7121) Subject: Re: carl9170: Beacons at lower Tx power than data frames? From: Harshal Chhaya To: Christian Lamparter Cc: linux-wireless@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Christian, Thanks for your patch - it definitely helped. My feedback to this (and some more info) is below. On Fri, Jul 15, 2011 at 9:22 AM, Christian Lamparter wrote: > On Thursday 14 July 2011 21:37:29 Harshal Chhaya wrote: >> I am working on an AP design that uses a TI-OMAP3 host processor with >> an Atheros AR9170 + AR9101 WLAN chipset. We are currently using >> carl9170 version 1.9.2 and carl9170 firmware version 1.9.4. > One question: have you considered ath9k_htc? I would certainly recommend > it over any ar9170 device. I was under the impression that AP mode support is better in carl9170 than in ath9k_htc. I had considered using AR9271 (which is a more recent chipset than the AR9170) but decided against it based on my understanding (which is based on the info on the wiki pages). If AR9271 (and ath9k_htc) are more stable and preferable to the AR9170 w/ carl9170, please let me know. Also, to clarify: my application is a wireless network that needs to support 60-70 802.11g clients connecting to the AP using WPA2-PEAP. All of the clients are battery powered and use the power save mechanisms of 802.11. Do you see any issues using AR9170 and carl9170 in this scenario? Also, I am running openWRT on an TI-OMAP3 processor @ 600 MHz. >> During network tests, several of the clients drop-off the network. > what tests? Also isn't there any verbose logs on the client/ap to why > they kick each other? The clients didn't have any helpful logs except that they disconnected due to not seeing any beacons for a few seconds. That's when I started looking at the beacons in more detail. >> The packet captures show that the beacons sent by the AP are at a much >> lower power than the other data packets. Is this wide variation in the AP's >> transmit power the expected behavior with this driver/firmware/chipset? >> If not, where do I look to fix this. > Try this: > --- > diff --git a/drivers/net/wireless/ath/carl9170/hw.h b/drivers/net/wireless/ath/carl9170/hw.h > index 261f893..3025f0b 100644 > --- a/drivers/net/wireless/ath/carl9170/hw.h > +++ b/drivers/net/wireless/ath/carl9170/hw.h > @@ -391,7 +391,39 @@ > > [patch snipped for brevity and also because it has been submitted in a separate email] This patch definitely helped stabilize the network. Thanks a lot for looking into this and providing the patch. However, I still see problems when I enable both WPA2 and power-save on the clients. Here is what I have tried so far: 30 802.11g clients open mode + power save - no problems, can send data to all 30 for hrs wpa2 + disable power save - no problems, can send data to all 30 for hrs wpa2 + enable power save - clients connect but then randomly disconnect every few seconds. My delay in replying is due to this odd behavior I was seeing. It took me a couple of days to figure out what was going on. Any suggestions on where to look for this problem? Thanks again, - Harshal