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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 730ACC4332B for ; Fri, 20 Mar 2020 12:56:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F3CC20739 for ; Fri, 20 Mar 2020 12:56:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727142AbgCTM4G (ORCPT ); Fri, 20 Mar 2020 08:56:06 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:45746 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726956AbgCTM4G (ORCPT ); Fri, 20 Mar 2020 08:56:06 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.93) (envelope-from ) id 1jFHBv-00Arb1-TM; Fri, 20 Mar 2020 13:56:00 +0100 Message-ID: Subject: Re: [PATCH 1/2] nl80211: vendor-cmd: qca: add dynamic SAR power limits From: Johannes Berg To: Kalle Valo , Brian Norris Cc: Jouni Malinen , Pkshih , "linux-wireless@vger.kernel.org" , "ath10k@lists.infradead.org" Date: Fri, 20 Mar 2020 13:55:58 +0100 In-Reply-To: <871rpqly6a.fsf@kamboji.qca.qualcomm.com> (sfid-20200317_175435_510355_7F89EC66) References: <1576684108-30177-1-git-send-email-kvalo@codeaurora.org> <1576684108-30177-2-git-send-email-kvalo@codeaurora.org> <1576748692.7758.17.camel@realtek.com> <20191219154828.GA12287@w1.fi> <20191219185522.GA16010@w1.fi> <871rpqly6a.fsf@kamboji.qca.qualcomm.com> (sfid-20200317_175435_510355_7F89EC66) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 (3.34.4-1.fc31) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Tue, 2020-03-17 at 18:54 +0200, Kalle Valo wrote: > For me either solutions are good enough, I'm not familiar enough with > all the different SAR user space interfaces to make a good decision. Brian probably has most insight into this :-) I really didn't want to have to be the referee here, I was hoping you'd figure this all out between yourselves... oh well. But as somebody has said on one of these threads, there seem to basically be two kinds of APIs: 1) some kind of platform-dependent index into a table that the driver/device has, or perhaps the BIOS; and 2) some kind of per-band (FSVO band) power restriction like here. The first is like iwlwifi, and I think Marvell was mentioned? But they're basically out - there's no information, and there's no clue as to which indices might even be valid, I think, nor what they mean. So there isn't really much value in a common API for that since you can't use it in a common fashion - arguably a common API would be worse... However, the case of 2, arguably the proposals are very similar? Qualcomm: optional nl80211_band, 1/2 dBm units Realtek: 2.4, four 5 GHz subbands, 1/4 dBm units Both have some strange namespace thing where the same namespace contains both the outer and inner attributes. Probably should think about the policy with NLA_POLICY_NESTED and see how that works. But it any case, these two don't seem like an insurmountable issue to combine? Say, something like defining a list of affected frequency ranges in the wiphy properties, and then giving a list of TX powers that matches the list of frequency ranges? We can go to 1/4 dBm or so, that's not such a big deal, I'd think? On the other hand, what does that actually buy us? If you cannot have common userspace that knows how a given platform must behave, then it's not very worthwhile to have common API for it? Brian, what do you think from a platform/userspace perspective - how do you actually determine the SAR limits? I'm guessing you just have a table of sorts, but how do you get the table? Would you actually have common userspace and benefit from having common API? johannes From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from s3.sipsolutions.net ([2a01:4f8:191:4433::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFHC7-00089Y-0r for ath10k@lists.infradead.org; Fri, 20 Mar 2020 12:56:12 +0000 Message-ID: Subject: Re: [PATCH 1/2] nl80211: vendor-cmd: qca: add dynamic SAR power limits From: Johannes Berg Date: Fri, 20 Mar 2020 13:55:58 +0100 In-Reply-To: <871rpqly6a.fsf@kamboji.qca.qualcomm.com> (sfid-20200317_175435_510355_7F89EC66) References: <1576684108-30177-1-git-send-email-kvalo@codeaurora.org> <1576684108-30177-2-git-send-email-kvalo@codeaurora.org> <1576748692.7758.17.camel@realtek.com> <20191219154828.GA12287@w1.fi> <20191219185522.GA16010@w1.fi> <871rpqly6a.fsf@kamboji.qca.qualcomm.com> (sfid-20200317_175435_510355_7F89EC66) MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Kalle Valo , Brian Norris Cc: Jouni Malinen , Pkshih , "linux-wireless@vger.kernel.org" , "ath10k@lists.infradead.org" On Tue, 2020-03-17 at 18:54 +0200, Kalle Valo wrote: > For me either solutions are good enough, I'm not familiar enough with > all the different SAR user space interfaces to make a good decision. Brian probably has most insight into this :-) I really didn't want to have to be the referee here, I was hoping you'd figure this all out between yourselves... oh well. But as somebody has said on one of these threads, there seem to basically be two kinds of APIs: 1) some kind of platform-dependent index into a table that the driver/device has, or perhaps the BIOS; and 2) some kind of per-band (FSVO band) power restriction like here. The first is like iwlwifi, and I think Marvell was mentioned? But they're basically out - there's no information, and there's no clue as to which indices might even be valid, I think, nor what they mean. So there isn't really much value in a common API for that since you can't use it in a common fashion - arguably a common API would be worse... However, the case of 2, arguably the proposals are very similar? Qualcomm: optional nl80211_band, 1/2 dBm units Realtek: 2.4, four 5 GHz subbands, 1/4 dBm units Both have some strange namespace thing where the same namespace contains both the outer and inner attributes. Probably should think about the policy with NLA_POLICY_NESTED and see how that works. But it any case, these two don't seem like an insurmountable issue to combine? Say, something like defining a list of affected frequency ranges in the wiphy properties, and then giving a list of TX powers that matches the list of frequency ranges? We can go to 1/4 dBm or so, that's not such a big deal, I'd think? On the other hand, what does that actually buy us? If you cannot have common userspace that knows how a given platform must behave, then it's not very worthwhile to have common API for it? Brian, what do you think from a platform/userspace perspective - how do you actually determine the SAR limits? I'm guessing you just have a table of sorts, but how do you get the table? Would you actually have common userspace and benefit from having common API? johannes _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k