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_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 4A979C10F14 for ; Tue, 23 Apr 2019 10:18:11 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 18AE72077C for ; Tue, 23 Apr 2019 10:18:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VH1dAcA0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 18AE72077C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sntech.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MnEc8ejG/zQabA7+URsX4AyrA9xCMouuxIkREZ5xlUo=; b=VH1dAcA0rKYMCd PzMl9vR9JHIWZbP90F4cU0CwwXDnCsMyJRiSqVFKRqP5kmtQLX3AryBK1kftMhv23PZsnvvWydkQA 0wpdjsj046u9gwjdz2KUSrJtsYTxpek6OIjHrqykuiT4exGdSup9yM4Z1PvXJGxoV78ttBAegpvSJ x0WQEQFF4d+6KKNlHF1Sy9pmzNabKcrzETgnFVdD1I2p77BRrWZSyaTPKpocS3F8aEY3Inl849HDu aQC0dEgB/bF4+FnMzJSw3aMZ8qSgoEirbR9wumnMaU/q6t/Q09kbvWKVKZsUp/AYnqo81NmDnaHA0 MIAd/exMYLYCRe5TdRwg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIsV0-00037m-Um; Tue, 23 Apr 2019 10:18:02 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIsUv-00036h-QM; Tue, 23 Apr 2019 10:17:59 +0000 Received: from p57b772a1.dip0.t-ipconnect.de ([87.183.114.161] helo=phil.localnet) by gloria.sntech.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hIsUl-0001mB-1B; Tue, 23 Apr 2019 12:17:47 +0200 From: Heiko Stuebner To: Douglas Anderson Subject: Re: [PATCH v2] clk: rockchip: undo several noc and special clocks as critical on rk3288 Date: Tue, 23 Apr 2019 12:17:46 +0200 Message-ID: <3726336.aAcGqF7Y7P@phil> In-Reply-To: <20190412161747.107107-1-dianders@chromium.org> References: <20190412161747.107107-1-dianders@chromium.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190423_031758_010544_2EFD0255 X-CRM114-Status: GOOD ( 20.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stephen Boyd , Michael Turquette , Elaine Zhang , linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, mka@chromium.org, ryandcase@chromium.org, Caesar Wang , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am Freitag, 12. April 2019, 18:17:47 CEST schrieb Douglas Anderson: > This is mostly a revert of commit 55bb6a633c33 ("clk: rockchip: mark > noc and some special clk as critical on rk3288") except that we're > keeping "pmu_hclk_otg0" as critical still. > > NOTE: turning these clocks off doesn't seem to do a whole lot in terms > of power savings (checking the power on the logic rail). It appears > to save maybe 1-2mW. ...but still it seems like we should turn the > clocks off if they aren't needed. > > About "pmu_hclk_otg0" (the one clock from the original commit we're > still keeping critical) from an email thread: > > > pmu ahb clock > > > > Function: Clock to pmu module when hibernation and/or ADP is > > enabled. Must be greater than or equal to 30 MHz. > > > > If the SOC design does not support hibernation/ADP function, only have > > hclk_otg, this clk can be switched according to the usage of otg. > > If the SOC design support hibernation/ADP, has two clocks, hclk_otg and > > pmu_hclk_otg0. > > Hclk_otg belongs to the closed part of otg logic, which can be switched > > according to the use of otg. > > > > pmu_hclk_otg0 belongs to the always on part. > > > > As for whether pmu_hclk_otg0 can be turned off when otg is not in use, > > we have not tested. IC suggest make pmu_hclk_otg0 always on. > > For the rest of the clocks: > > atclk: No documentation about this clock other than that it goes to > the CPU. CPU functions fine without it on. Maybe needed for JTAG? > > jtag: Presumably this clock is only needed if you're debugging with > JTAG. It doesn't seem like it makes sense to waste power for every > rk3288 user. In any case to do JTAG you'd need private patches to > adjust the pinctrl the mux the JTAG out anyway. > > pclk_dbg, pclk_core_niu: On veyron Chromebooks we turn these two > clocks on only during kernel panics in order to access some coresight > registers. Since nothing in the upstream kernel does this we should > be able to leave them off safely. Maybe also needed for JTAG? > > hsicphy12m_xin12m: There is no indication of why this clock would need > to be turned on for boards that don't use HSIC. > > pclk_ddrupctl[0-1], pclk_publ0[0-1]: On veyron Chromebooks we turn > these 4 clocks on only when doing DDR transitions and they are off > otherwise. I see no reason why they'd need to be on in the upstream > kernel which doesn't support DDRFreq. > > Signed-off-by: Douglas Anderson applied for 5.2 Thanks Heiko _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel