From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 372BDC433ED for ; Sun, 11 Apr 2021 11:26:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3E5D610A6 for ; Sun, 11 Apr 2021 11:26:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235366AbhDKL1F (ORCPT ); Sun, 11 Apr 2021 07:27:05 -0400 Received: from dispatch1-us1.ppe-hosted.com ([148.163.129.48]:52176 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233696AbhDKL1E (ORCPT ); Sun, 11 Apr 2021 07:27:04 -0400 X-Greylist: delayed 587 seconds by postgrey-1.27 at vger.kernel.org; Sun, 11 Apr 2021 07:27:04 EDT Received: from dispatch1-us1.ppe-hosted.com (localhost.localdomain [127.0.0.1]) by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 772B9227EA0 for ; Sun, 11 Apr 2021 11:17:01 +0000 (UTC) Received: from mx1-us1.ppe-hosted.com (unknown [10.7.67.81]) by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 2F0106005F; Sun, 11 Apr 2021 11:17:01 +0000 (UTC) X-Virus-Scanned: Proofpoint Essentials engine Received: from mx1-us1.ppe-hosted.com (cache2.dclocal [10.7.64.219]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 2428F1A005E; Sun, 11 Apr 2021 11:17:00 +0000 (UTC) Received: from mail3.candelatech.com (mail2.candelatech.com [208.74.158.173]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id B7AC8780068; Sun, 11 Apr 2021 11:16:59 +0000 (UTC) Received: from [192.168.254.6] (unknown [50.34.172.155]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail3.candelatech.com (Postfix) with ESMTPSA id 8A10413C2B3; Sun, 11 Apr 2021 04:16:58 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 mail3.candelatech.com 8A10413C2B3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=candelatech.com; s=default; t=1618139819; bh=4Il3VsbAY3QKC6UEhsF2QOTodNnxO3lqbT5oWJGX6dU=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=P7ShuHQrVtJV4zBbMWH7q2z/jq0uxvSV68Uwjc8TaL5EJdsCna5kPBy1+AI2x65DG c7GJ5Z5plAe3J+GfUn4PM8L5GKBoDtkJumfC6m/qg1aNNwo0VuvEZpm4CKdeLG4ECR HoT1s3Dt83aZLeJamb/yEOKemK4fOUu4QmxWMIaE= Subject: Re: [PATCH 06/12] iwlwifi: mvm: Add support for 6GHz passive scan To: "Peer, Ilan" , Luca Coelho , "kvalo@codeaurora.org" Cc: "linux-wireless@vger.kernel.org" References: <20210331091452.543321-1-luca@coelho.fi> From: Ben Greear Organization: Candela Technologies Message-ID: Date: Sun, 11 Apr 2021 04:16:58 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-MW Content-Transfer-Encoding: 7bit X-MDID: 1618139820-6v4eKNU07ua6 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 4/11/21 3:14 AM, Peer, Ilan wrote: > Hi Ben, > >> -----Original Message----- >> From: Ben Greear >> Sent: Wednesday, March 31, 2021 15:04 >> To: Luca Coelho ; kvalo@codeaurora.org >> Cc: linux-wireless@vger.kernel.org >> Subject: Re: [PATCH 06/12] iwlwifi: mvm: Add support for 6GHz passive scan >> >> On 3/31/21 2:14 AM, Luca Coelho wrote: >>> From: Ilan Peer >>> >>> When doing scan while 6GHz channels are not enabled, the 6GHz band is >>> not scanned. Thus, if there are no APs on the 2GHz and 5GHz bands >>> (that will allow discovery of geographic location etc. that would >>> allow enabling the 6GHz channels) but there are non collocated APs on >>> 6GHz PSC channels these would never be discovered. >>> >>> To overcome this, FW added support for performing passive UHB scan in >>> case no APs were discovered during scan on the 2GHz and 5GHz channels. >>> >>> Add support for enabling such scan when the following conditions are >>> met: >>> >>> - 6GHz channels are supported but not enabled by regulatory. >>> - Station interface is not associated or less than a defined time >>> interval passed from the last resume or HW reset flows. >>> - At least 4 channels are included in the scan request >>> - The scan request includes the widlcard SSID. >>> - At least 50 minutes passed from the last 6GHz passive scan. >> >> Why are you trying so hard to not do passive scans? This seems like it is set >> up for all sorts of frustration. >> > > This logic enables a special 'passive' scan which is not directly intended for discovery of APs for connection etc. but > for discovery of APs with country information in the beacons/probe responses, so the fw could use this information > as an input that might allow it to enable 6GHz channels (which are supported but are disabled). This special scan > is intended for cases that the device does not have any other regulatory information that allows it to enable the 6GHz channels. > Once these channels are enabled, we use passive scan as needed. > > We generally try to avoid passive scan on all the 6GHz channels as this is a long flow that takes at least 6 seconds (as there are > such 64 channels) and with the discovery mechanisms defined for the 6GHz is not really needed. If the station comes up and does a 6E passive scan and does not find any AP, perhaps because 6Ghz AP was turned on 1 minute after the station tried to initially scan, this means that it will take 50 minutes before it can have a chance to scan the AP and connect to the Internet? If station cannot connect after a relatively short time, then I think it should scan as widely as it can in order find some possible way to connect. And why care about 'at least 4 channels'. If we know the AP channel, and can scan exactly there, then your concern about taking a long time is resolved. How else can we tell the radio that 6E is allowed? I previously tried all sorts of things to enable 6E channels so that I could more easily set the radio to sniff one of those channels in monitor mode, and I had no luck. If all of the 6E channels are marked as passive, what harm is it to enable the channels in the regdom from the beginning? Thanks, Ben > > Hope this clarifies things. > > Regards, > > Ilan. > -- Ben Greear Candela Technologies Inc http://www.candelatech.com