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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B58B1CFB440 for ; Mon, 7 Oct 2024 11:54:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=doWR+a1Wt/mAjJePybgdiDgPX3ULBSPYW0JlBfU8QRQ=; b=Nn/AoXxwi+7PGjjbSxZPe0zxOD r7Zyg3OJIsm0AZVXyA33Wya/+4b6MnSLorq07OW2yYmdnMGgZDNWXccSNbQvmUN+UgIkHDgQ9c52I fv4F2Ra9lTlz+Z8wVQa5bjxrXNtFZJCxxZz3e5a3ChF9nvuB4ihnAePq/Ve73gSXrlblwcLkuKmHz Qt/MoOzz1wQnCd8xb6RbbN6YfYN+nz+v66RznuOx2MY6bboAH6PjgsoqcQxSH0rd2MXSJjsDkbVfo 5ZryIy/59Q+vAbPRreUEeVzaIT7GzqIK5pNfxvLmPM9AE5zuv2lUP5jctbRmFjmlD5yS7lp0hM4mP /39j0yfA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sxmJW-00000002F5I-1KQI; Mon, 07 Oct 2024 11:54:10 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sxmIE-00000002EtX-0tFn for linux-arm-kernel@lists.infradead.org; Mon, 07 Oct 2024 11:52:51 +0000 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 E7F0EFEC; Mon, 7 Oct 2024 04:53:16 -0700 (PDT) Received: from pluto (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6B2C43F640; Mon, 7 Oct 2024 04:52:45 -0700 (PDT) Date: Mon, 7 Oct 2024 12:52:33 +0100 From: Cristian Marussi To: Florian Fainelli Cc: linux-arm-kernel@lists.infread.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sudeep Holla , Cristian Marussi , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list , "open list:SYSTEM CONTROL & POWER/MANAGEMENT INTERFACE" , "moderated list:SYSTEM CONTROL & POWER/MANAGEMENT INTERFACE" , justin.chen@broadcom.com, opendmb@gmail.com, kapil.hali@broadcom.com, bcm-kernel-feedback-list@broadcom.com, Arnd Bergmann Subject: Re: [PATCH] firmware: arm_scmi: Give SMC transport precedence over mailbox Message-ID: References: <20241006043317.3867421-1-florian.fainelli@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241006043317.3867421-1-florian.fainelli@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241007_045250_312667_8588AEA7 X-CRM114-Status: GOOD ( 13.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Oct 05, 2024 at 09:33:17PM -0700, Florian Fainelli wrote: > Broadcom STB platforms have for historical reasons included both > "arm,scmi-smc" and "arm,scmi" in their SCMI Device Tree node compatible > string. Hi Florian, did not know this.. > > After the commit cited in the Fixes tag and with a kernel > configuration that enables both the SCMI and the Mailbox transports, we > would probe the mailbox transport, but fail to complete since we would > not have a mailbox driver available. > Not sure to have understood this... ...you mean you DO have the SMC/Mailbox SCMI transport drivers compiled into the Kconfig AND you have BOTH the SMC AND Mailbox compatibles in DT, BUT your platform does NOT physically have a mbox/shmem transport and as a consequence, when MBOX probes (at first), you see an error from the core like: "arm-scmi: unable to communicate with SCMI" since it gets no reply from the SCMI server (being not connnected via mbox) and it bails out .... am I right ? If this is the case, without this patch, after this error and the mbox probe failing, the SMC transport, instead, DO probe successfully at the end, right ? IOW, what is the impact without this patch, an error and a delay in the probe sequence till it gets to the SMC transport probe 9as second attempt) or worse ? (trying to understand here...) Thanks, Cristian