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=-4.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=unavailable 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 3B531C4360F for ; Mon, 11 Mar 2019 19:10:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1208220643 for ; Mon, 11 Mar 2019 19:10:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b="jXg9ybgv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbfCKTKc (ORCPT ); Mon, 11 Mar 2019 15:10:32 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:40738 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728086AbfCKTK1 (ORCPT ); Mon, 11 Mar 2019 15:10:27 -0400 Received: by mail-lj1-f193.google.com with SMTP id w6so89027ljd.7 for ; Mon, 11 Mar 2019 12:10:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cogentembedded-com.20150623.gappssmtp.com; s=20150623; h=subject:from:to:cc:references:organization:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YczbOIkJjnyOhE8i2q5XcBo6cUbwyvzdRTSxex0tgjI=; b=jXg9ybgv5sS2NxUSyul7eJFcPH75NhRjt3iWwtWkaCNfftV7TK5c0IeUDi618XBLTv EjUssXBmrxtvWbndJBVkqrn+ViRaWX24ye/JYToFMx26wUdL3WiRkwshpqbkBPURKOzM 8fgwOmBdi21maRL6u5AHPqAQ2SNnU/lkuV85BFgEX05Yghu0YlbWNHB1OWku6VG7lQFL xl4JnmoQfaMSALhAnQuidYeXkyC8Hs3xird9Skxlu9ybD/OjvW9FJVphnfUD+4RyX0Ke SemFr8VWOrsUyhWkzoYrv8z7LzGIUWJWe2A4aZOusBAxN+C0MqDrvFOYspBgKn0xGhdl fJBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=YczbOIkJjnyOhE8i2q5XcBo6cUbwyvzdRTSxex0tgjI=; b=tH75xXi2WYg1AoBqDA5IgQjwOo3T1GiGT1Dj0ea+j2wtmH5ISkKSIsrV/O5DdR0u2/ 3c3tRDL+CcrGxFf4WsYKEFSRkdXAQzaMP0whCVRqFEWwl0SEhreb00eteo/reMBrP9Nm 3jhVF/klkB86sTC52PAQky1AwNkhP7UhQK+iJdh+peV2riXNyC823tZ2IOFV3AqAbFsv jHbTmLsJMmXpRGQB+5qYfdFAhpHLPL4jq+7pY/1qoVh/nj9cAFtGzmcVM8MGvo41EaQf JHD+41TJDDOqfmnWY7AaH5SMdD6nzSmKz0n5qYp3cOzxMRgpRD8PH5PYwaXP+uhMfEw6 fjFg== X-Gm-Message-State: APjAAAX0uKOASv2or8V2n8bVt+Q4hZ82IdUwx2v5S79QR+sIFccVGUat gX4LxAXIJ5no9XvnshPIU2qHsnEEIYY= X-Google-Smtp-Source: APXvYqyUrtGqclO4nC1PTW62XVcet3koA1FjLtqaGSKdaGWAzyGEU7WmgPaQ9Mo8qwmYbAwnUcUPJQ== X-Received: by 2002:a2e:9cda:: with SMTP id g26mr16719406ljj.48.1552331425121; Mon, 11 Mar 2019 12:10:25 -0700 (PDT) Received: from wasted.cogentembedded.com ([31.173.87.168]) by smtp.gmail.com with ESMTPSA id i15sm1052339ljb.48.2019.03.11.12.10.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Mar 2019 12:10:23 -0700 (PDT) Subject: Re: [PATCH] clk: renesas: r8a77980-cpg-mssr: fix RPC-IF module clock's parent From: Sergei Shtylyov To: Geert Uytterhoeven Cc: Linux-Renesas , Michael Turquette , Stephen Boyd , Geert Uytterhoeven , linux-clk References: <981d0e06-76b8-fe69-1a8e-91661ad0faba@cogentembedded.com> Organization: Cogent Embedded Message-ID: <0bc9b0ee-61cb-1834-59ad-632fe289f9ab@cogentembedded.com> Date: Mon, 11 Mar 2019 22:10:22 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <981d0e06-76b8-fe69-1a8e-91661ad0faba@cogentembedded.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-MW Content-Transfer-Encoding: 7bit Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On 03/11/2019 08:14 PM, Sergei Shtylyov wrote: [...] > No hangs were seen on V3M, despite the RPCD2 clock remained disabled. > The RPC clocks on both V3H and V3M suffer from a lack of clear documentation... > >> See also section 62.4.7 (Frequency change), which does not have a >> subsection for V3H, but it may be impacted (changing RPCD2 causes >> an additional read of RPCCKR, satisfying the read-after-write requirement >> documented there). > > Hmm, haven't seen this item before; it looks like we can't use the standard > divider component. BTW, this section in the 1.50 manual tells to use the soft > reset on V3MOK. OK, I'll investigate this... Now I have: the frequency change didn't seem to happen, and without RPCD2 enabled the CMNCR read still hangs, even when I added readl() call into clk_writel(). So I think my patch was correct. >>> Fixes: 94e3935b5756 ("clk: renesas: r8a77980: Add RPC clocks") >>> Signed-off-by: Sergei Shtylyov > [...] MBR, Sergei