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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 A28CDC433DF for ; Mon, 12 Oct 2020 09:32:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6379520776 for ; Mon, 12 Oct 2020 09:32:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387446AbgJLJc0 (ORCPT ); Mon, 12 Oct 2020 05:32:26 -0400 Received: from foss.arm.com ([217.140.110.172]:33004 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726104AbgJLJc0 (ORCPT ); Mon, 12 Oct 2020 05:32:26 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 71F7D31B; Mon, 12 Oct 2020 02:32:25 -0700 (PDT) Received: from bogus (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 58E223F66B; Mon, 12 Oct 2020 02:32:24 -0700 (PDT) Date: Mon, 12 Oct 2020 10:32:12 +0100 From: Sudeep Holla To: Etienne Carriere Cc: linux-kernel@vger.kernel.org, "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , Cristian Marussi , Vincent Guittot , Sudeep Holla , Souvik Chakravarty Subject: Re: [PATCH 1/5] firmware: arm_scmi: always initialize protocols Message-ID: <20201012092827.GB16519@bogus> References: <20201008143722.21888-1-etienne.carriere@linaro.org> <20201008191727.ht26r5dnh3iwqj5n@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 09, 2020 at 02:31:55PM +0200, Etienne Carriere wrote: > On Thu, 8 Oct 2020 at 21:17, Sudeep Holla wrote: > > > > On Thu, Oct 08, 2020 at 04:37:18PM +0200, Etienne Carriere wrote: > > > Remove the IDR replacement that prevent initializing an SCMI protocol > > > when it has already been initialized. This is needed when there are > > > several SCMI agents that do implement a given SCMI protocol unless > > > what only the related SCMI protocol communication is initialized only > > > for first probed agent. > > > > > > > Can you please elaborate on your usecase please. What do you mean by several > > SCMI agents here. OSPM is the only agent we are interested here. What > > other agents is this driver supposed to handle here. We allocate memory > > in init and calling init multiple times messes up the allocated and > > initialised structures. > > > > So NACK for this patch as it needs more work if we need this at all. > > > > Hello Sudeep, > > Considering a device with several SCMI servers spread over several co-processor > and possibly also in the Arm TZ secure world, each of these servers > uses a specific SCMI channel. Without this change, each SCMI protocol gets > initialized only for the first agent device that is probed. > Fair enough, but it also adds complexity. Do you have a master SCMI server implementation in that case. As some protocols like system might need to be broadcast to all servers and master server needs to take appropriate action. > My setup is also a bit specific. My device has several secure configuration > features that can individually be enabled or not. For example, configuring > domain X as secure makes some clocks reachable by Linux only through SCMI, > and configuring domain Y as secure makes other clocks reachable by Linux > only through SCMI. For flexibility, I expose domain X resources (here clocks) > to an Linux agent whereas domain Y resources (here clocks also) are > exposed to another agent, each agent with its specific transport/channel. > Enabling each agent node in the Linux FDT allows to define which SCMI clocks > get exposed and hence registered in the kernel. > Without the change proposed here, I cannot get the clocks exposed to both > agents when enabled as the SCMI clock protocol is initialized only for the 1st > probbed agent device. > OK, as Cristian has already mentioned we need to clean up a bit on these initcalls and Cristian has some WIP patches, I would like to wait and look at them instead of breaking other usecases with patch(multiple devices per protocol within one scmi server) -- Regards, Sudeep