From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 49CD418A6AD; Mon, 7 Oct 2024 11:52:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728301970; cv=none; b=ajPZYmupGyNvaH4CyJsJNysF4Qz4cRmo6afKK/G33YnDQdUDBZFtBnYsm0EDV3DuceLHRwbBEnv7WAWX1wzKC44y0imG86pAb1+TzngFh7yLsYVj7KDtzqf/wt4u5XtEcUgbJgG/p3ACE+TT8kPGf2437zh2shCIizhNAOW8Ij4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728301970; c=relaxed/simple; bh=AAXY8T10Y18po9ZtgYdQspsWDx7aM51t75JyZ9VnPfo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Mpm+nTld6JT4llKDuoMzr0lxplXzbjBTCAFDKP6hyC2CRyk3a2DbQfUvm+ObDFO7msQLJfa/Hnp/K01QupnZgi0eInQVTymeVaoQJS+AhuE4QqJJcp5IJtosj/sDqTsEpkSqQLMwlNlVdJBTMGvPvtYeBpbireX9LsB6PBcx0NA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241006043317.3867421-1-florian.fainelli@broadcom.com> 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