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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 C2975C04AAC for ; Mon, 20 May 2019 20:28:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99CE320863 for ; Mon, 20 May 2019 20:28:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726238AbfETU2G convert rfc822-to-8bit (ORCPT ); Mon, 20 May 2019 16:28:06 -0400 Received: from gloria.sntech.de ([185.11.138.130]:58048 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725989AbfETU2G (ORCPT ); Mon, 20 May 2019 16:28:06 -0400 Received: from ip5f5a6320.dynamic.kabel-deutschland.de ([95.90.99.32] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hSot6-0008TP-VJ; Mon, 20 May 2019 22:28:01 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Doug Anderson Cc: Matthias Kaehlcke , Rob Herring , Mark Rutland , Linux ARM , "open list:ARM/Rockchip SoC..." , devicetree@vger.kernel.org, LKML Subject: Re: [PATCH 1/2] ARM: dts: rockchip: Limit GPU frequency on veyron mickey to 300 MHz when the CPU gets very hot Date: Mon, 20 May 2019 22:28:00 +0200 Message-ID: <1695268.0xytyHHoPs@diego> In-Reply-To: References: <20190520170132.91571-1-mka@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 20. Mai 2019, 22:16:46 CEST schrieb Doug Anderson: > Hi, > > On Mon, May 20, 2019 at 10:01 AM Matthias Kaehlcke wrote: > > > > On rk3288 the CPU and GPU temperatures are correlated. Limit the GPU > > frequency on veyron mickey to 300 MHz for CPU temperatures >= 85°C. > > > > This matches the configuration of the downstream Chrome OS 3.14 kernel, > > the 'official' kernel for mickey. > > > > Signed-off-by: Matthias Kaehlcke > > --- > > Note: this patch depends on "ARM: dts: rockchip: Add #cooling-cells > > entry for rk3288 GPU" (https://lore.kernel.org/patchwork/patch/1075005/) > > --- > > arch/arm/boot/dts/rk3288-veyron-mickey.dts | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/arm/boot/dts/rk3288-veyron-mickey.dts b/arch/arm/boot/dts/rk3288-veyron-mickey.dts > > index d889ab3c8235..f118d92a49d0 100644 > > --- a/arch/arm/boot/dts/rk3288-veyron-mickey.dts > > +++ b/arch/arm/boot/dts/rk3288-veyron-mickey.dts > > @@ -125,6 +125,12 @@ > > <&cpu2 8 THERMAL_NO_LIMIT>, > > <&cpu3 8 THERMAL_NO_LIMIT>; > > }; > > + > > + /* At very hot, don't let GPU go over 300 MHz */ > > + cpu_very_hot_limit_gpu { > > + trip = <&cpu_alert_very_hot>; > > + cooling-device = <&gpu 2 2>; > > + }; > > Two things: > > A) If I'm reading things properly, you're actually limiting things to > 400 MHz. This is because you don't have > which deletes the 500 MHz GPU operating point. So on upstream the > available points are: > > 0: 600 MHz > 1: 500 MHz > 2: 400 MHz > 3: 300 MHz > 4: 200 MHz > 5: 100 MHz > > ...and downstream: > > 0: 600 MHz > 1: 400 MHz > 2: 300 MHz > 3: 200 MHz > 4: 100 MHz > > Thinking about it more, I bet Heiko would actually be OK deleting the > 500 MHz GPU operating point for veyron. Technically it's not needed > upstream because upstream doesn't have our hacks to allow re-purposing > NPLL for HDMI (so they _can_ make 500 MHz) but maybe we can make the > argument that these laptops have only ever been tested with the 500 > MHz operating point removed and also that eventually someonje will > probably figure out a way to re-purpose NPLL for HDMI even upstream... Yeah. Dropping the opp sounds sensible ... for the npll-related thing and also if you're really running into thermal constraints it might be good to give the system a bit more breathing room? Heiko > B) It seems like in the same patch you'd want to introduce > "cpu_warm_limit_gpu", AKA: > > cpu_warm_limit_gpu { > trip = <&cpu_alert_warm>; > cooling-device = > <&gpu 1 1>; > }; > > > -Doug