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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C899BC433F5 for ; Thu, 21 Apr 2022 00:06:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383364AbiDUAJ3 (ORCPT ); Wed, 20 Apr 2022 20:09:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376861AbiDUAJX (ORCPT ); Wed, 20 Apr 2022 20:09:23 -0400 Received: from mail-pg1-f182.google.com (mail-pg1-f182.google.com [209.85.215.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9396313FB7 for ; Wed, 20 Apr 2022 17:06:35 -0700 (PDT) Received: by mail-pg1-f182.google.com with SMTP id g9so3184198pgc.10 for ; Wed, 20 Apr 2022 17:06:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=IfHap1dlOBr5gDAC0VqPSKp2nHM5B6kQ59uiY70TBVI=; b=pyAdiIQH847Xev3lFbrgJG64tw7GejGY/WfX3oAg312bnNLK4hmpIaqot9kWjxeJhe 2jjJtnNAPBqtCVzpQ0xu+7wOG14ld8qf35HMQ53oF/ippK28GiOqjjLFn5kRpFL0c+A9 NqbT74EPPobnFYZf20wWfr7XdlUWExPupT6eBZNWr8Jsom6kuYwxB1La5eoqnjgitVLw jNKH9utBxGcBurzt7e6rst1y2df/nOyedwS2kjvVLv8JwnI1Y+R5nUFSUskyk6Dd5v6+ eJ6Ht02o3PtVMd3pOQ6vjXKCAza2An1tlXdgnSOd2pZEaPtaBMK/rR3yCp5wOH/ow0IM ysew== X-Gm-Message-State: AOAM5328H8/skW/LEJcfpgeQsaOZLEPGXuKYZw7g26//gjopmy8YudlF UqkdBZPFwU0RR//SZeximctArQ== X-Google-Smtp-Source: ABdhPJyBccHfNaH1A30eRpDRBC9j4Q7GiILCDsil3xPBkNRkvmISVOA5FX0e7H26MH7xr/3847BX1w== X-Received: by 2002:a05:6a00:1ac8:b0:4fa:917f:c1aa with SMTP id f8-20020a056a001ac800b004fa917fc1aamr26016985pfv.2.1650499594990; Wed, 20 Apr 2022 17:06:34 -0700 (PDT) Received: from localhost (c-71-197-186-152.hsd1.wa.comcast.net. [71.197.186.152]) by smtp.gmail.com with ESMTPSA id u10-20020a62d44a000000b0050ad4053840sm639105pfl.149.2022.04.20.17.06.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Apr 2022 17:06:33 -0700 (PDT) From: Kevin Hilman To: Roger Lu , Matthias Brugger , Enric Balletbo Serra , Rob Herring , Nicolas Boichat , Stephen Boyd , Philipp Zabel Cc: Fan Chen , HenryC Chen , Xiaoqing Liu , Charles Yang , Angus Lin , Mark Rutland , Nishanth Menon , Roger Lu , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Project_Global_Chrome_Upstream_Group@mediatek.com, Guenter Roeck , Jia-wei Chang Subject: Re: [PATCH v24 3/7] soc: mediatek: SVS: introduce MTK SVS engine In-Reply-To: <20220420102044.10832-4-roger.lu@mediatek.com> References: <20220420102044.10832-1-roger.lu@mediatek.com> <20220420102044.10832-4-roger.lu@mediatek.com> Date: Wed, 20 Apr 2022 17:06:33 -0700 Message-ID: <7h5yn3s3jq.fsf@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Roger, Roger Lu writes: > The Smart Voltage Scaling(SVS) engine is a piece of hardware > which calculates suitable SVS bank voltages to OPP voltage table. > Then, DVFS driver could apply those SVS bank voltages to PMIC/Buck > when receiving OPP_EVENT_ADJUST_VOLTAGE. > > Signed-off-by: Roger Lu > Reviewed-by: AngeloGioacchino Del Regno Can SVS work with one or the other clusters disabled? It seems like it should still be able to work. However, if you disable the 2nd cluster (e.g. by passing `maxcpus=4` on the kernel command-line, the SVS driver will fail to probe. I dont' think it's a blocker for merging this series, but making the probe a bit more robust so it can handle the cluster being disabled would be nice additional fix for later. For example, upstream kernel on mt8183-pumpkin board is very unstable with the 2nd cluster enabled (I'm still trying to debug why), but I have to boot with `maxcpus=4` on the cmdline, otherwise kernel fails to boot, so that's how I noticed this probe failure with SVS. Kevin