Return-path: Received: from mail-fx0-f217.google.com ([209.85.220.217]:41704 "EHLO mail-fx0-f217.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755786AbZIKT03 convert rfc822-to-8bit (ORCPT ); Fri, 11 Sep 2009 15:26:29 -0400 Received: by fxm17 with SMTP id 17so1020651fxm.37 for ; Fri, 11 Sep 2009 12:26:31 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <43e72e890909111136r67a305b9qc3e78a7dcb205d@mail.gmail.com> References: <200909111427.39974.hs4233@mail.mn-solutions.de> <43e72e890909111136r67a305b9qc3e78a7dcb205d@mail.gmail.com> From: =?ISO-8859-1?Q?G=E1bor_Stefanik?= Date: Fri, 11 Sep 2009 21:26:11 +0200 Message-ID: <69e28c910909111226s48ac1db9ya8fe2cce54861c1e@mail.gmail.com> Subject: Re: Questions about regulatory domain & passive scanning To: "Luis R. Rodriguez" Cc: Holger Schurig , linux-wireless@vger.kernel.org, Kel Modderman Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Sep 11, 2009 at 8:36 PM, Luis R. Rodriguez wrote: > On Fri, Sep 11, 2009 at 5:27 AM, Holger Schurig > wrote: >> Hi ! >> >> I'm playing with regulatory domain using wireless-testing, iw, >> crda and ath5 on Debian. Here are some observations: >> >> 1) Debian sucks here > > We've tried a few times to poke them and after some thread exchanges > and some changes to wirless-regdb and crda due to concerns over the > signing stuff due to the DFSG in account for these discussions it > seems some stuff was packaged but not sure where it went. Kel, are you > aware of the status in this regard on Debian? Well, if the problem is signing, then they are always free to package a patched crda that accepts unsigned or self-signed databases; AFAIK GPL doesn't prohibit that (though it kinda defeats the purpose of crda). > > [1] http://lists.alioth.debian.org/pipermail/pkg-wpa-devel/2009-May/002267.html > >> 2) I remove CONFIG_WIRELESS_OLD_REGULATORY. Then, after inserting >> ? the card, I see in "iw list": >> >> ? ? ? ? * 2412 MHz [1] (20.0 dBm) >> ? ? ? ? * 2417 MHz [2] (20.0 dBm) >> ? ? ? ? * 2422 MHz [3] (20.0 dBm) >> ? ? ? ? * 2427 MHz [4] (20.0 dBm) >> ? ? ? ? * 2432 MHz [5] (20.0 dBm) >> ? ? ? ? * 2437 MHz [6] (20.0 dBm) >> ? ? ? ? * 2442 MHz [7] (20.0 dBm) >> ? ? ? ? * 2447 MHz [8] (20.0 dBm) >> ? ? ? ? * 2452 MHz [9] (20.0 dBm) >> ? ? ? ? * 2457 MHz [10] (20.0 dBm) >> ? ? ? ? * 2462 MHz [11] (20.0 dBm) >> ? ? ? ? * 2467 MHz [12] (20.0 dBm) (passive scanning) >> ? ? ? ? * 2472 MHz [13] (20.0 dBm) (passive scanning) >> ? ? ? ? * 2484 MHz [14] (20.0 dBm) (passive scanning) >> >> ? I'd like to highlight the "passive scanning". Is this info >> ? from the card EEPROM? > > If you lack crda, by default you will world roam, even if your EEPROM > has been programmed to a specific regulatory domain and calibrated as > such -- reason being is we moved regulatory content to userspace; so > OLD_REG had only 3 statically built regulatory domains in the kernel, > with CRDA you get all of them on userspace, and no more need to update > the kernel to update regulatory settings. World roaming has some > enhancements though like enabling active scanning on passive-scanning > channels if youo pick up a beacon from an AP on that channel. > >> 3) After "iw reg set DE" (for germany), it's now >> >> ? ? ? ? ?2412 MHz [1] (20.0 dBm) >> ? ? ? ? ?2417 MHz [2] (20.0 dBm) >> ? ? ? ? ?2422 MHz [3] (20.0 dBm) >> ? ? ? ? ?2427 MHz [4] (20.0 dBm) >> ? ? ? ? ?2432 MHz [5] (20.0 dBm) >> ? ? ? ? ?2437 MHz [6] (20.0 dBm) >> ? ? ? ? ?2442 MHz [7] (20.0 dBm) >> ? ? ? ? ?2447 MHz [8] (20.0 dBm) >> ? ? ? ? ?2452 MHz [9] (20.0 dBm) >> ? ? ? ? ?2457 MHz [10] (20.0 dBm) >> ? ? ? ? ?2462 MHz [11] (20.0 dBm) >> ? ? ? ? ?2467 MHz [12] (20.0 dBm) (passive scanning) >> ? ? ? ? ?2472 MHz [13] (20.0 dBm) (passive scanning) >> ? ? ? ? ?2484 MHz [14] (disabled) >> >> ? Great, CRDA worked obviously: channel 14 has been disabled. > > Sure, but keep in mind your regulatory domain must've been read too > first, that's probably what lifted your passive scan flag on channel > 12 unless you did a scan prior to trying to set the regulatory domain. > >> ? And, as I understand it, CRDA can just limit settings >> ? further, not widening it. Therefore channels 12 and 13 >> ? are still marked as "passive scanning". > > Right. Now if your card is world roaming (defined in > net/wireless/reg.c as reg_is_world_roaming() ) you could lift passive > scan off of 12 and 13 if you had an AP there. > >> ? If I want to get them to "active scanning", would I need to >> ? modify the EEPROM of the card? > > Well yes, but you must note that is something not supported, not > recommended, unless you are a manufacturer selling cards and have the > capability to calibrate, etc, and certify. That is -- EEPROM > programming is not something designed to be changed by the end user. > >>?ath_info says "Reg. Domain: >> ? 0x60". > > Ok, as I have documented on the ath wiki page [1] any Atheros > regulatory domain which has 0x60 is world roaming. As I also > documented as well these 12 world regulatory domains are statically > built into the kernel on ath as they are custom world regulatory > domains, so even without the presence of CRDA you'll get the > regulatory domain your card is designed for. With OLD_REG though you > end up trying to stick to static kenrel US rules so you would only be > allowed to use what the US allows on your 0x60 regulatory domain, this > is ath_world_regdom_60_61_62 on drivers/net/wireless/ath/regd.c. > > [1] http://wireless.kernel.org/en/users/Drivers/ath > > ?Luis > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at ?http://vger.kernel.org/majordomo-info.html > -- Vista: [V]iruses, [I]ntruders, [S]pyware, [T]rojans and [A]dware. :-)