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=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 A554A7D00B for ; Tue, 28 Aug 2018 12:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727162AbeH1Pxd (ORCPT ); Tue, 28 Aug 2018 11:53:33 -0400 Received: from mail.bootlin.com ([62.4.15.54]:42430 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727085AbeH1Pxc (ORCPT ); Tue, 28 Aug 2018 11:53:32 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 213DE2079D; Tue, 28 Aug 2018 14:02:11 +0200 (CEST) Received: from bbrezillon (AAubervilliers-681-1-53-19.w90-88.abo.wanadoo.fr [90.88.170.19]) by mail.bootlin.com (Postfix) with ESMTPSA id 67AB1206A6; Tue, 28 Aug 2018 14:02:10 +0200 (CEST) Date: Tue, 28 Aug 2018 14:02:09 +0200 From: Boris Brezillon To: vitor Cc: , Sekhar Nori , Wolfram Sang , , Jonathan Corbet , , 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" , , , Geert Uytterhoeven , Linus Walleij , Xiang Lin , Przemyslaw Gaj , Peter Rosin Subject: Re: [PATCH v6 01/10] i3c: Add core I3C infrastructure Message-ID: <20180828140209.29155d00@bbrezillon> In-Reply-To: References: <20180719152930.3715-1-boris.brezillon@bootlin.com> <20180719152930.3715-2-boris.brezillon@bootlin.com> <20180824143934.6d6b6487@bbrezillon> <20180824201600.7d80bca9@bbrezillon> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org 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? > > 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 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. 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. Regards, Boris