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=-8.5 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 8494AC43610 for ; Thu, 15 Nov 2018 09:46:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49C8920825 for ; Thu, 15 Nov 2018 09:46:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="Hvc9TnhK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49C8920825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387915AbeKOTx5 (ORCPT ); Thu, 15 Nov 2018 14:53:57 -0500 Received: from mail-wm1-f66.google.com ([209.85.128.66]:37143 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728634AbeKOTx4 (ORCPT ); Thu, 15 Nov 2018 14:53:56 -0500 Received: by mail-wm1-f66.google.com with SMTP id p2-v6so17237054wmc.2 for ; Thu, 15 Nov 2018 01:46:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=Sa3kl/RsjKWO+z6SiPlqidK82hY1mr0ur092VFUOkug=; b=Hvc9TnhKlehbUHjKPaiBDz5attI7I+wYSLh51MLpJ+eNQOGP+XvngiocaMnKDtu+1f Bf3zLY+D025HUG61N+Kch7XAk57Reh1GvqeC/M9mD/ylAkgHC2v74GdevWIpoIjnZB4/ LE2D5zyl6XVltLRNrcybf7WA+jnzzEHUZqoE4Ls1qYvst68jGjgCqFMQGXd99Lvz5EYK E9FYlqtkEk7C4P0xgVLfGiwKS9HrIJlMHrOUwzOZeoZZDr1gBvmIn+w0fvv43T0BI3zW tNRNy5i8Goc8R23dqT2yhXCJaUukUhJsl8J52WYTXcGgBwYUQ+e8JXxE3Edpe58KeN+g sx7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=Sa3kl/RsjKWO+z6SiPlqidK82hY1mr0ur092VFUOkug=; b=bFZnrpIIlUFxW0Yq5Es5XcmEOoKc4xPOQ1xEWiEizvpfDHYC24DvwhvhABqpGNZx7D 457SrRtKrWRRiwC2hZVsyN/pO0PDsvCM9UZSlrVkVi1dDlAuPWYqm2uk5irmr1lHkAsD NfCc/WXYQvo8rNE/UZDmjpTtlIts41hsdF3TS8NUwM+qZEiuKMmuk5fJxRdMYqd719se NmySTGbhLseiZlw1T5LOOh8BXbwQuFnjC6gSSyVgnp0nF/sB36ttPNqJaVN7DjN3ZdDx Kfq6Kb5ktDBwsn+gCXrXFJwEaShzioLproxYu4r124N4Ht3yFirsRhk3v9WL71NAN3P6 sutQ== X-Gm-Message-State: AGRZ1gI8n5pB3hA+eviawaJf/NXb87xyT+XLvxl3AK6/CgNKC5ctYyUk uhsZf9gQJCPt0ZHnonEwWD4w4w== X-Google-Smtp-Source: AJdET5ec4VYABAIx97zKtMEl91kHSFI522CxXZHs5m5Fzho1KOKbdonjkjwCFKFBhqoDTg90XkhVyQ== X-Received: by 2002:a1c:c545:: with SMTP id v66mr4879066wmf.132.1542275209188; Thu, 15 Nov 2018 01:46:49 -0800 (PST) Received: from boomer.baylibre.com ([2a01:e34:eeb6:4690:106b:bae3:31ed:7561]) by smtp.gmail.com with ESMTPSA id m7sm5251705wml.32.2018.11.15.01.46.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 15 Nov 2018 01:46:48 -0800 (PST) Message-ID: <533bd2bd4dced1610a803e7b2d51995e5577ba1d.camel@baylibre.com> Subject: Re: [RFC v1 5/7] clk: meson: meson8b: mark the CPU clock as CLK_IS_CRITICAL From: Jerome Brunet To: Martin Blumenstingl , linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org, narmstrong@baylibre.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mturquette@baylibre.com, sboyd@kernel.org Date: Thu, 15 Nov 2018 10:46:46 +0100 In-Reply-To: <20181114225725.2821-6-martin.blumenstingl@googlemail.com> References: <20181114225725.2821-1-martin.blumenstingl@googlemail.com> <20181114225725.2821-6-martin.blumenstingl@googlemail.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.2 (3.30.2-2.fc29) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-11-14 at 23:57 +0100, Martin Blumenstingl wrote: > We don't want the common clock framework to disable the "cpu_clk" if > it's not used by any device. The cpufreq-dt driver does not enable the > CPU clocks. However, even if it would we would still want the CPU clock > to be enabled at all times because the CPU clock is also required even > if we disable CPU frequency scaling on a specific board. > > The reason why we want the CPU clock to be enabled is a clock further up > in the tree: > Since commit 6f888e7bc7bd58 ("clk: meson: clk-pll: add enable bit") the > sys_pll can be disabled. However, since the CPU clock is derived from > sys_pll we don't want sys_pll to get disabled. The common clock > framework takes care of that for us by enabling all parent clocks of our > CPU clock when we mark the CPU clock with CLK_IS_CRITICAL. > > Until now this is not a problem yet because all clocks in the CPU > clock's tree (including sys_pll) are read-only. However, once we allow > modifications to the clocks in that tree we will need this. > > Signed-off-by: Martin Blumenstingl > --- > drivers/clk/meson/meson8b.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c > index 8a3c346e110d..d566dd5bc567 100644 > --- a/drivers/clk/meson/meson8b.c > +++ b/drivers/clk/meson/meson8b.c > @@ -646,7 +646,8 @@ static struct clk_regmap meson8b_cpu_clk = { > "cpu_scale_out_sel" }, > .num_parents = 2, > .flags = (CLK_SET_RATE_PARENT | > - CLK_SET_RATE_NO_REPARENT), > + CLK_SET_RATE_NO_REPARENT | > + CLK_IS_CRITICAL), > }, > }; > Acked-by: Jerome Brunet