From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id E7DFF7DE71 for ; Thu, 30 Aug 2018 13:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729136AbeH3SAD (ORCPT ); Thu, 30 Aug 2018 14:00:03 -0400 Received: from smtprelay.synopsys.com ([198.182.60.111]:54956 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729083AbeH3SAC (ORCPT ); Thu, 30 Aug 2018 14:00:02 -0400 Received: from mailhost.synopsys.com (mailhost2.synopsys.com [10.13.184.66]) by smtprelay.synopsys.com (Postfix) with ESMTP id 627D810C122B; Thu, 30 Aug 2018 06:57:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1535637466; bh=6k1zoRLzZSG94an35JBtchiqePVUaxsoLDtDTl5MnTs=; h=Subject:To:CC:References:From:Date:In-Reply-To:From; b=H5aVCmCWQKMf+/L3JB7Yh1asXZ3rbiJ6nj9boLOBOUP3IkiR2Bpz9ccOSgtbupnGn HzesXCsT2smEq4dAI9fzj/MrI5Br3q/iN2aVhdo+IaObnAK4yW9j8KM59xHifMIRsX fzrgp7vwHtosthDIBgEw3PDNRQvl7F8avo54OSHiyKgzmg4VDqJjwHmonCimG6QUzj nl7w0bSlX2rZDYvujEBQ3wjCs1eXdN1uRvbMRbiYAtGHuXbIw8BdAtWJZ38qbtzQIr yRSs5/+bpHWfpeIC1SCkGFVS3Yi0cq6CqoAMF9dNMgecKYOKP7BkSxRvFMNE5KNsv+ m/r2DsyzP1I4g== Received: from US01WEHTC3.internal.synopsys.com (us01wehtc3.internal.synopsys.com [10.15.84.232]) by mailhost.synopsys.com (Postfix) with ESMTP id D9BCA3ADF; Thu, 30 Aug 2018 06:57:42 -0700 (PDT) Received: from DE02WEHTCB.internal.synopsys.com (10.225.19.94) by US01WEHTC3.internal.synopsys.com (10.15.84.232) with Microsoft SMTP Server (TLS) id 14.3.361.1; Thu, 30 Aug 2018 06:57:42 -0700 Received: from DE02WEHTCA.internal.synopsys.com (10.225.19.92) by DE02WEHTCB.internal.synopsys.com (10.225.19.94) with Microsoft SMTP Server (TLS) id 14.3.361.1; Thu, 30 Aug 2018 15:57:40 +0200 Received: from [10.0.2.15] (10.107.25.44) by DE02WEHTCA.internal.synopsys.com (10.225.19.80) with Microsoft SMTP Server (TLS) id 14.3.361.1; Thu, 30 Aug 2018 15:57:39 +0200 Subject: Re: [PATCH v6 01/10] i3c: Add core I3C infrastructure To: Przemyslaw Gaj , Boris Brezillon , vitor CC: "linux-gpio@vger.kernel.org" , Sekhar Nori , Wolfram Sang , "linux-i2c@vger.kernel.org" , Jonathan Corbet , "linux-doc@vger.kernel.org" , Greg Kroah-Hartman , Arnd Bergmann , Przemyslaw Sroka , Arkadiusz Golec , Alan Douglas , Bartosz Folta , Damian Kos , Alicja Jurasik-Urbaniak , Cyprian Wronka , Suresh Punnoose , Rafal Ciepiela , Thomas Petazzoni , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , "Kumar Gala" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Geert Uytterhoeven , Linus Walleij , Xiang Lin , Peter Rosin References: <20180719152930.3715-1-boris.brezillon@bootlin.com> <20180719152930.3715-2-boris.brezillon@bootlin.com> <20180824143934.6d6b6487@bbrezillon> <20180824201600.7d80bca9@bbrezillon> <20180828140209.29155d00@bbrezillon> <4DBE768F-3CDC-41BE-9CC8-E294E7277CB1@cadence.com> From: vitor Message-ID: <8abfb007-d755-36a4-5960-fddd61d04aa2@synopsys.com> Date: Thu, 30 Aug 2018 14:57:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <4DBE768F-3CDC-41BE-9CC8-E294E7277CB1@cadence.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.107.25.44] Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi Przemyslaw On 28-08-2018 13:55, Przemyslaw Gaj wrote: > Hi Vitor, > > I have already implemented Mastership request/handover but we are waiting for Boris’s patch to be accepted and merged. Anyway, my comments below. > > On 8/28/18, 2:02 PM, "Boris Brezillon" wrote: > > EXTERNAL MAIL > > > Hi Vitor, > > On Tue, 28 Aug 2018 12:50:12 +0100 > vitor wrote: > > > Hi Boris, > > > > The DT Bindings say "The node describing an I3C bus should be named > > i3c-master.". Do you have a field for secondary master? > > I think we don’t need separate field for secondary master. Main and secondary masters > support similar functionalities. It’s enough to have this state internally and do mastership it it's needed. Yes, you are right. > > > > > On 24-08-2018 19:16, Boris Brezillon wrote: > > > Well, before even considering supporting secondary master registration, > > > we need to handle mastership handover. As for the DAA operation, it's > > > likely to be host specific, so we'll have to add a new hook to the > > > i3c_master_controller_ops struct. > > Do you mean when master try to delegate the bus ownership through > > GETACCMST? or to get the bus ownership with IBI-MR? > > I think we need to support both. > > I agree. That's ok to me. > > > > > I think that could be useful to pass the ibi type on request_ibi(), > > there is some case where the master doesn't support IBI-MR. > > Actually, I was planning on making it completely separate from > regular slave IBIs. That is, the master controller driver would demux > the slave, MR and Hot Join IBIs, and if there's an MR request, queue a > mastership handover work to the workqueue (pretty much what we do for > Hot-Join already). Mastership handover is anyway likely to be IP > specific, so I don't think there's a need to make it look like a > regular IBI. > > I think it's better to have separate function to do mastership request. > > Regarding whether IBI-MR support should be exposed to the I3C framework > or not depends on how much will be automated on the framework side. I > don't the answer yet, but that's probably something will figure out > along the road. > > My current implementation is: when request_mastership field > of i3c_master_controller_ops structure is set, master driver supports mastership requests. > That's how I check if this is supported or not. > > Regards, > > Boris > > Regards, > Przemek > when you say request_mastership, do you mean the current master do the mastership hand-off or the secondary master request to be current master? So, per my understanding since the Main master support the hand-off of the bus you accept all incoming MR, right? Or do you check all devices BCR? Best regards, Vitor Soares