Return-path: Received: from mx1.redhat.com ([209.132.183.28]:49939 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932574AbbLBVHE (ORCPT ); Wed, 2 Dec 2015 16:07:04 -0500 Message-ID: <1449090422.21648.12.camel@redhat.com> (sfid-20151202_220714_478105_205A5309) Subject: Re: [PATCH 08/11] brcmfmac: Make 5G join preference configurable. From: Dan Williams To: Paul Stewart Cc: Arend van Spriel , Jouni Malinen , Kalle Valo , linux-wireless , Hante Meuleman Date: Wed, 02 Dec 2015 15:07:02 -0600 In-Reply-To: References: <1448447567-12189-1-git-send-email-arend@broadcom.com> <1448447567-12189-9-git-send-email-arend@broadcom.com> <87si3nkb2l.fsf@kamboji.qca.qualcomm.com> <565D5B77.7050501@broadcom.com> <87d1uqijnz.fsf@kamboji.qca.qualcomm.com> <20151201110827.GA4362@w1.fi> <565EF307.90002@broadcom.com> <1449074331.21648.2.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2015-12-02 at 10:00 -0800, Paul Stewart wrote: > From my perspective it is useful to have the driver express whether > or not it supports this parameter. It may not change how the system > operates, but it will be useful in testing to determine whether it > is expected that a (given version of a) driver is expected to act > with respect to this property so we can flag issues with the > implementation. Agreed. Dan > On Wed, Dec 2, 2015 at 8:38 AM, Dan Williams wrote: > > On Wed, 2015-12-02 at 14:32 +0100, Arend van Spriel wrote: > > > On 12/01/2015 12:08 PM, Jouni Malinen wrote: > > > > On Tue, Dec 01, 2015 at 11:48:32AM +0200, Kalle Valo wrote: > > > > > Arend van Spriel writes: > > > > > > It solves a problem for us, but admittedly it is not > > > > > > something > > > > > > that is > > > > > > very usable by user-space apps. So I guess what you are > > > > > > suggesting > > > > > > here is to come up with a nl80211 api for this. On the > > > > > > mailing > > > > > > list > > > > > > (or hostap list) the topic pops up from time to time so > > > > > > there > > > > > > are > > > > > > people who would like to have such a knob to play with. > > > > > > Still > > > > > > would > > > > > > like to keep the module parameter although its use may > > > > > > change > > > > > > when > > > > > > nl80211 api is added. > > > > > > > > > > I don't know what is the best approach, that's why I would > > > > > like > > > > > to hear > > > > > opinions from others. Personally I don't like the idea of > > > > > adding > > > > > 802.11 > > > > > level configuration options to module parameters, but on the > > > > > other hand > > > > > I don't have any strong opinions about this. > > > > > > > > I would like to see this as a new attribute to > > > > NL80211_CMD_CONNECT > > > > to > > > > provide parameters for offloaded (driver and/or firmware) BSS > > > > selection > > > > and roaming. If there is a driver that uses roaming offload > > > > with > > > > NL80211_CMD_ASSOCIATE, the same attribute could be used there > > > > (but > > > > I'm > > > > not sure how exact such offloading would work in practice since > > > > I'd > > > > expect both authentication and (re)association to be > > > > offloaded). > > > > > > Sounds reasonable. Just would like to explore the use-case a bit > > > more. > > > Looking at tools like NetworkManager and android network list, > > > the > > > user > > > is always presented with just SSID listed once. For > > > NetworkManager > > > > > While NM has band locking properties, there is currently no "prefer > > 5ghz" since as Jouni said, the supplicant should probably just > > prefer > > 5ghz right now. In any case, the best path from an NM perspective > > would be a supplicant per-network property that would then be sent > > for > > CONNECT-capable drivers, or which the supplicant would manually > > handle > > for softmac drivers through its existing AP selection code. > > > > Dan > > > > > details can be configured for a connection and the bss selection > > > parameters could be one of those. What level of detail would be > > > needed > > > there. Not saying we can not have more detail in the nl80211 API. > > > > > > > > I guess we have two different designs, one where the roaming > > > > > logic is in > > > > > firmware and other where wpasupplicant is responsible for > > > > > this. > > > > > (And I > > > > > assume that brcfmac belongs to the former group.) Ideally it > > > > > would be > > > > > nice that we would have a same configuration knob for both > > > > > but I > > > > > don't > > > > > know if that's really feasible. > > > > > > > > Both of these would work as long as wpa_supplicant has means > > > > for > > > > providing such configuration to the driver in a generic manner. > > > > That > > > > NL80211_CMD_CONNECT extension with a new optional attribute > > > > would > > > > be > > > > such a generic design. > > > > > > So does the driver need to advertise support for bss selection > > > parameters or can it simply ignore the parameters. Assuming the > > > latter > > > for now. > > > > > > Regards, > > > Arend > > > -- > > > 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 > > -- > > 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