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=-5.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,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 6F8ABC433E7 for ; Fri, 9 Oct 2020 17:03:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36B112225F for ; Fri, 9 Oct 2020 17:03:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DCep2uQD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390112AbgJIRDb (ORCPT ); Fri, 9 Oct 2020 13:03:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389892AbgJIRDa (ORCPT ); Fri, 9 Oct 2020 13:03:30 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADA45C0613D2 for ; Fri, 9 Oct 2020 10:03:30 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id d23so4744663pll.7 for ; Fri, 09 Oct 2020 10:03:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=/5wUWQqgMKt7EGmPaNqqLH40EmDYIrJnvSXrx5dUlfw=; b=DCep2uQD5hojSI+iubeC4ePB1JKrfcPeMCDgdyK1NcM+Lu1tOEpMv/owXhhHzOyk/b eEn0mvP5cuStSnehisWFtPm25Wt28Otk25unezJKareUfkyDhkkChIAxtPMsgh/v5eoT IWOAhxdClc21cwJejzXAUnhxUAvcRv8FVLT8vscGqIeXuRQMdepUg2/CIP0KTs2rRj/x ykKvQT05no5w53AuHLR8M/KiKROLbFkyQaG9xjxD7Ae2WIInZi1vcptAjXHJFmqbjlUE 6lPpf5OAKLEdilHeWZ8cT5QuOOCRgl/trSimnYJOc5Y+T2nIct4IiASUn88FEWtqNK7U UnTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=/5wUWQqgMKt7EGmPaNqqLH40EmDYIrJnvSXrx5dUlfw=; b=Vc4gSOOfYlbZliuj3b/sZMrjv1SWkJmSdQR4ir9Fbqd/PDO3Ly16TWjQ3y7qtOK08G C7FeZf0wmfJuRLAwBHvwP8jWkKyvC7kOslyBlcFFM3bElNL6MwzmJ/aQz6nIICRkB+XM QvwVLsa2ZX16ZRBPTB6omh17zTZrvPMcoQ1U0YLCTjuEUmWkLgkNfxbZEpc1FUOzqld4 LSx7JlqkHbM/02GFUGrox2EJwct0KkSu3y4sLbyp1fqkLYPgVvKA6GAXVOI1MtfDyjHo 1n32fpuol0a2dt60oDhX6Gt5/d2Gk+u2X22foGDAsgCo9pT6l1+g25gokViC45gdKvF5 iFvg== X-Gm-Message-State: AOAM533gtYKL1qOQV1kFgg+NZf3+8+4Hu7vnpZj+TnJfjOsmvyn20VBm aI0UMqw9tlpGld/UgtXqwqg= X-Google-Smtp-Source: ABdhPJx3JUTkvfsPcw7gs1d2kYtotEv4gnjk+LmY9OMqeL/Ogeywcwyswcg09r+xu5odjV+nopaxWA== X-Received: by 2002:a17:902:aa44:b029:d3:8b4f:5083 with SMTP id c4-20020a170902aa44b02900d38b4f5083mr12653891plr.78.1602263010127; Fri, 09 Oct 2020 10:03:30 -0700 (PDT) Received: from [10.230.29.112] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id b4sm3932644pjz.51.2020.10.09.10.03.28 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 09 Oct 2020 10:03:29 -0700 (PDT) Subject: Re: [PATCH v3 2/2] mailbox: Add Broadcom STB mailbox driver To: Sudeep Holla , Jim Quinlan Cc: bcm-kernel-feedback-list@broadcom.com, Jassi Brar , Florian Fainelli , open list , "moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE" References: <20200919192235.43872-1-james.quinlan@broadcom.com> <20200919192235.43872-3-james.quinlan@broadcom.com> <20201009163848.5tbl5bmvuoj2de2v@bogus> From: Florian Fainelli Message-ID: Date: Fri, 9 Oct 2020 10:03:27 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.3.2 MIME-Version: 1.0 In-Reply-To: <20201009163848.5tbl5bmvuoj2de2v@bogus> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/2020 9:38 AM, Sudeep Holla wrote: > On Sat, Sep 19, 2020 at 03:22:30PM -0400, Jim Quinlan wrote: >> only implements the agent-to-platform channel; > > In that case any reason why you can't reuse the existing smc transport > for SCMI. It was added recently in case you haven't checked the latest > kernel version(v5.8 or above). Check out for drivers/firmware/arm_scmi/smc.c > IIUC rather vaguely Florian was cc-ed on those patches. Our firmware completes all commands by posting an interrupt and we already have platforms in the field with this mailbox driver. I was hoping we could make use of the SMC transport, but the current firmware implementation completes commands by raising an interrupt. The reason why we did that was that we could support synchronous and asynchronous calls the same way. > >> we may implement the platform-to-agent channel in the future. > > This is not yet support with that transport, it is hard to generalise > as different vendors have their own solutions there. > >> An unusual aspect of this driver is how the completion of an SCMI message >> is indicated. An SCMI message is initiated with an ARM SMC call, but the >> return of this call does not indicate the execution or completion of the >> message. Rather, the message's completion is signaled by an interrupt. >> > > So are these not fast SMC/HVC calls then ? If so we may need some changes > to that driver. I just rejected multiple message support as we had assumed > fast smc/hvc. > -- Florian