Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:27305 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755323Ab3J1VLw (ORCPT ); Mon, 28 Oct 2013 17:11:52 -0400 Message-ID: <526ED316.7090205@qca.qualcomm.com> (sfid-20131028_221155_409318_F4E04BFD) Date: Mon, 28 Oct 2013 14:11:50 -0700 From: Jeffrey Johnson MIME-Version: 1.0 To: Dan Williams CC: "Chauhan, Rajesh" , "Rodriguez, Luis" , Johannes Berg , "linux-wireless@vger.kernel.org" , "Malinen, Jouni" , "Bahini, Henri" , "Chang, Leo" , "Luo, Xun" Subject: Re: [PATCH] cfg80211/nl80211: Add support to report unsafe frequency ranges(s) References: <1381985833-31312-1-git-send-email-rajeshc@qca.qualcomm.com> <1382020835.14410.16.camel@jlt4.sipsolutions.net> <1382035171.22901.13.camel@dcbw.foobar.com> <1382986906.7298.10.camel@dcbw.foobar.com> In-Reply-To: <1382986906.7298.10.camel@dcbw.foobar.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 10/28/2013 12:01 PM, Dan Williams wrote: > On Mon, 2013-10-28 at 18:08 +0000, Chauhan, Rajesh wrote: >> Hi Luis, >> >> For "enough information for proper usage" - how about if I add an attribute for the source of interference (say, for example, "cellular") for each of those frequency range? > When you say "cellular" here, do mean a WWAN card in the same machine, > sharing the antenna (or using a very very nearby antenna) with the WiFi > card? Or do you mean a close-by phone, or a tower itself? How is this > different from BT coexistence or WiMAX coexistence? > One use case would be a colocated WWAN card sharing an antenna or using a very very nearby antenna. There could be other use cases. I would say this is complimentary to coexistence. The idea is to tell userspace which frequencies have know sources of interference so that they can be avoided, and hence coexistence would not be required. If userspace chooses to use an "unsafe" frequency, the the driver's coexistence logic would then be utilized, but the user experience could suffer compared to if a "safe" frequency had been selected. The issue that has been debated internally is whether or not userspace needs to know the source of the interference. In other words, if we have an enumerated set of interference sources, would userspace behave differently based upon the source? This is, after all, just meant to be a hint to userspace to give it more information to use when selected a channel to be used in a master mode of operation.