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 C0CC4C25B0E for ; Tue, 16 Aug 2022 16:05:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231962AbiHPQFQ (ORCPT ); Tue, 16 Aug 2022 12:05:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236277AbiHPQEd (ORCPT ); Tue, 16 Aug 2022 12:04:33 -0400 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB8D4B0D for ; Tue, 16 Aug 2022 09:03:17 -0700 (PDT) Received: by mail-wr1-x431.google.com with SMTP id a4so1444958wrq.1 for ; Tue, 16 Aug 2022 09:03:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:from:to:cc; bh=G75P1MnBlTsTHdbk47o07Tr2GO1weW34E0V486dZ6zQ=; b=tyvhRkLnT9eQhPU1fA+R37bcZOcR1lj7033nZZYaHV0lalSjYk16myN81RvmFzEdMC ndbWIqX+3WeqaBeA4NYeiFOOZplsWmWVG0eBlinEroNkv6X42hD+OZDgFfIEM4+D8HHD jSBOg9RNYMjSTCVrPWaO51iBtkm4g6kvHMAvaboPSNjUjSUQppwDWKdo0SOc5ZvywH3a wdIkH7/7oG1wUDHRaCoQkUtwjPuA7EqYTuXWezQTRwsFT3XlB2A0Sl44lhrlkRDchgsU km96AAvMAwoVwbguS/wwzFqyDDP7ykeHS0+J50yUk0jwdDc04LdcT9/4QOpcIJt9h7Ni Le3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:x-gm-message-state:from:to:cc; bh=G75P1MnBlTsTHdbk47o07Tr2GO1weW34E0V486dZ6zQ=; b=f19aJw1p9zou5/Qd/IKpievltd08gP3i/GtVGsTaiqvER1R89oeqQkymtTmPbcJoT3 tUhKdMo/BDP63Ws8za4P9prAPUDZHrZdZemr4sbDE7XB/S4mA9eoogrqSYLfVZ/9/HVn q0WqYxgDvoJe4yLjseYVFIhTx16IWDAyq4gt8bTj43sN5ZjohOf6ipWao0sjeVO7+blt 7kGdK/9m7VOgyvgUfUiYXwVhh33DXjRK432kwh/el3fJtcOrtTdz5YI7Y6V8u9ghcWqU sQ5v+9BSQXGJe1mbciAqpvJ2mEAcaJxEv49Xu7z2R8VRGfI+wXCcCbEPxzLlVvfXzTc8 tWUw== X-Gm-Message-State: ACgBeo3hX768rFqxVIS0WslBI5JoQQswE1DXa0sKKaRmsqbzBEVSaDbe 1Co/VfM/2MKxwWh9XZvGK6vaJw== X-Google-Smtp-Source: AA6agR4sDP2eoSMqKaV2coqQ9MbRDM82FgU7mJBsnWOywpv4YY3XTlQ/jWnKNtxaFziuNPY74Dlivg== X-Received: by 2002:a05:6000:82:b0:225:21ff:a389 with SMTP id m2-20020a056000008200b0022521ffa389mr76896wrx.22.1660665795549; Tue, 16 Aug 2022 09:03:15 -0700 (PDT) Received: from localhost ([109.180.234.208]) by smtp.gmail.com with ESMTPSA id z3-20020a1cf403000000b003a60bc8ae8fsm1897992wma.21.2022.08.16.09.03.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Aug 2022 09:03:15 -0700 (PDT) From: Punit Agrawal To: "Yuan, Perry" Cc: Punit Agrawal , "rafael.j.wysocki@intel.com" , "Huang, Ray" , "viresh.kumar@linaro.org" , "Sharma, Deepak" , "Limonciello, Mario" , "Fontenot, Nathan" , "Deucher, Alexander" , "Su, Jinzhou (Joe)" , "Huang, Shimmer" , "Du, Xiaojian" , "Meng, Li (Jassmine)" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v5 6/7] cpufreq: amd-pstate: update pstate frequency transition delay time References: <20220814163548.326686-1-Perry.Yuan@amd.com> <20220814163548.326686-7-Perry.Yuan@amd.com> <87bkslim2c.fsf@stealth> Date: Tue, 16 Aug 2022 17:03:13 +0100 In-Reply-To: (Perry Yuan's message of "Tue, 16 Aug 2022 07:02:27 +0000") Message-ID: <874jycfa66.fsf@stealth> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi Perry, "Yuan, Perry" writes: > [AMD Official Use Only - General] > > Hi Punit > >> -----Original Message----- >> From: Punit Agrawal >> Sent: Monday, August 15, 2022 11:06 PM >> To: Yuan, Perry >> Cc: rafael.j.wysocki@intel.com; Huang, Ray ; >> viresh.kumar@linaro.org; Sharma, Deepak ; >> Limonciello, Mario ; Fontenot, Nathan >> ; Deucher, Alexander >> ; Su, Jinzhou (Joe) ; >> Huang, Shimmer ; Du, Xiaojian >> ; Meng, Li (Jassmine) ; linux- >> pm@vger.kernel.org; linux-kernel@vger.kernel.org >> Subject: Re: [PATCH v5 6/7] cpufreq: amd-pstate: update pstate frequency >> transition delay time >> >> [CAUTION: External Email] >> >> Perry Yuan writes: >> >> > Change the default transition latency to be 20ms that is more >> > reasonable transition delay for AMD processors in non-EPP driver mode. >> > >> > Update transition delay time to 1ms, in the AMD CPU autonomous mode >> > and non-autonomous mode, CPPC firmware will decide frequency at 1ms >> > timescale based on the workload utilization. >> > >> > Acked-by: Viresh Kumar >> > Signed-off-by: Perry Yuan >> > --- >> > drivers/cpufreq/amd-pstate.c | 4 ++-- >> > 1 file changed, 2 insertions(+), 2 deletions(-) >> > >> > diff --git a/drivers/cpufreq/amd-pstate.c >> > b/drivers/cpufreq/amd-pstate.c index e40177d14310..9cb051d61422 100644 >> > --- a/drivers/cpufreq/amd-pstate.c >> > +++ b/drivers/cpufreq/amd-pstate.c >> > @@ -41,8 +41,8 @@ >> > #include >> > #include "amd-pstate-trace.h" >> > >> > -#define AMD_PSTATE_TRANSITION_LATENCY 0x20000 >> > -#define AMD_PSTATE_TRANSITION_DELAY 500 >> > +#define AMD_PSTATE_TRANSITION_LATENCY 20000 >> > +#define AMD_PSTATE_TRANSITION_DELAY 1000 >> >> How were these values derived? If from documentation, it'll be good to add a >> link to the relevant documentation. And if they were derived from testing, >> please mention this in the commit log (along with some details of the tests used >> to determine the value). > > The values are calculated from the CPU PM firmware and hardware design. > There are some latency and delay values defined in the PM firmware, I have no documents about the detail for now. In that case, please mention that the values are calculated from firmware / hardware design in the commit log (and include a reference to the firmware sources if available). Thanks! [...]