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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 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 A3EC7C43215 for ; Mon, 25 Nov 2019 13:09:49 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 79B2A20836 for ; Mon, 25 Nov 2019 13:09:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="DYgGuriG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79B2A20836 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=oKgnRV54FoRlguFCZ0WWGQeHMSVBKKyhwOSG5UG9qqI=; b=DYgGuriGlkq5g/ cCgXEW6dbQE6MdGBLUZASNfU/dw71/dLkyI61pQmcmv7ktq+vUrgXZWqhijfc+059A+bu/CjuF64E XOVOToxEqFLG+U7DHCp0/Ec9rkEnfwbGNq+eNq/zRPBH6TOKrPs6tWrCeEw3ICL6N7uwm8T9TI7Zy jCcRb/PxSMs8LIJnh5yMN8s1mtUronS+S6Quk1TDHKrl2yzKf3NOA+ymfvGvAAs5UH2Jdqd9+HVYk LVrt+AG5A3YUaDOxpu/abnjd+K7vg0C/40dKVZQUxJfoW0DGfWy5k4ObKZuyuFfxF6/f3EtYAzvj7 W32Pflx2IcvuvmuXHBug==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iZE7h-00087F-5M; Mon, 25 Nov 2019 13:09:49 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iZE7c-00086X-MB for linux-i3c@lists.infradead.org; Mon, 25 Nov 2019 13:09:47 +0000 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 7223B28FD16; Mon, 25 Nov 2019 13:09:41 +0000 (GMT) Date: Mon, 25 Nov 2019 14:09:36 +0100 From: Boris Brezillon To: Vitor Soares Subject: Re: I3C Mastership RFC Message-ID: <20191125140936.47f3d479@collabora.com> In-Reply-To: References: <20191112084127.6efc6fac@collabora.com> <20191114061011.GA25288@global.cadence.com> <20191114133214.0b6ecc0a@collabora.com> <20191125080220.GA30630@global.cadence.com> <20191125123452.7c2549dd@collabora.com> <20191125115502.GA5777@global.cadence.com> <20191125132219.2e45d084@collabora.com> Organization: Collabora X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191125_050944_984092_71047432 X-CRM114-Status: GOOD ( 18.85 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux I3C List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Przemyslaw Gaj , "linux-i3c@lists.infradead.org" , "bbrezillon@kernel.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org On Mon, 25 Nov 2019 13:00:17 +0000 Vitor Soares wrote: > > > > > > I'm pretty sure we solved that already (that's what > > > > > > i3c_master_acquire_bus_ownership() calls are supposed to take care of). > > > > > > Can you be a bit more specific? What makes you think the master might > > > > > > not be in control of the bus when i3c_dev_do_priv_xfers_locked() is > > > > > > called? > > > > > > > > > > You are assuming that after i3c_master_acquire_bus_ownership() return, > > > > > secondary master already owns the bus. Main master can ack the MR request > > > > > and not send the CETACCMST immediately. > > > > > > > > > > > > > In Cadence HC driver, I'm waiting for GETACCMST longer, polling the > > > > status and after I exit from ->request_mastership(), I'm the bus owner. > > > > If not, error exit code is returned and we can't make the transfers. > > > > Are you able to implement the same behavior? > > > > > > You can assume everyone will do in that way. What happen if you receive a > > > request or an information from current master? > > > > We have this ->request_mastership() method so controllers that have > > this logic (MR+wait(GETACCMST) automated can still interface with the > > subsystem. > > I can also poll the GETACCMST but we are assuming nothing will happen > between MR and GETACCMST. Nothing coming from the master that tries to acquire the bus, yes. Nothing coming from the current master, no, and that shouldn't be a problem as long as those operations don't involve acquiring bus->lock. And if some of those operation involve acquiring the lock (I'd still need to understand which operation that would be) they'll just be delayed/rejected. > > > If your controller handles the MR/GETACCMST separately, it > > shouldn't be hard to implement, and we can even provide an helper if > > people end up duplicating the code. > > I already implement a callback in my code so each controller be able to > do their stuff in that in request/deliver mastership. Can you share some details here? What would those callbacks supposed to do and when would they be called? _______________________________________________ linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c