From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 779481D9A41; Thu, 14 Nov 2024 10:22:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731579770; cv=none; b=REqOaNi8WsfM9U6SajmwtJb4H/HgODlCNSx1KosBQXkhFt2CyQjRBSUjyTwcuQxeSI0o3sLOxkMp/YD6MGNXNFfuhz9kzB3dPVJEspCanbu2rO8kA/ZU+wSFP2OeKQVyih8xs0gcy/eE/brta0y1XrX9+gevwJR0SPk+/xsgSL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731579770; c=relaxed/simple; bh=N0Zs06FQ5Xtv3SHbCA4mOGMqJ8tnWHRBdA2cSQ+32Nk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QJaoHyx7ki6zz02bPmQ3F7z5ch4Poob8lTf28Ildq92oGRi1W1+pbWkKw31wEgxc2U8GVb8pMDkJpUFALYshLOnGopSsnGvsp0zDp+936nd3wnS808gBU4NohL3+yj7EvpjDE6pJ363x8HltBBdLeKNiXj1mLRaiI6oNkuKsBKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=BS56wmC8; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="BS56wmC8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1731579766; bh=N0Zs06FQ5Xtv3SHbCA4mOGMqJ8tnWHRBdA2cSQ+32Nk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=BS56wmC8dD7ZOfnypazCktbot14vilOAIeneaG4ZyzWr8JY5UbLY16X5RL4jskCm5 I0dOZNQfcpaWMdiaft42eej+JtjZhga4BY+ss563+AkGfe081OWzH8vHnpanKdEc1E uU0UbM1jokCZf8z8uWVIjpNQlvOIIv/OHLaXg6WSobK04nOrAeZIQQVRhQQ26YdWWy TL/YD2iHuEzY/bEMbN6MMTdGGBsu47DUSHaZHgrF1uv58IFgK5j4DYge2cgP46Qnfv HsSOmcjyrzOuImoVNZ4CU3SV6oU+MBQVfjL6iLLm6NP7Lz/xqs8X9awWH/WWgh6tgG +qdRy0lMeLfRA== Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id 34DE117E14EF; Thu, 14 Nov 2024 11:22:46 +0100 (CET) Message-ID: <9f9a969f-6ce5-4e6c-89bd-51fe121db693@collabora.com> Date: Thu, 14 Nov 2024 11:22:45 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/4] cpufreq: mediatek: CCI support SoC , the transition_delay set to 10 ms To: Mark Tseng , "Rafael J . Wysocki" , Viresh Kumar , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Matthias Brugger Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Project_Global_Chrome_Upstream_Group@mediatek.com References: <20241108063942.19744-1-chun-jen.tseng@mediatek.com> <20241108063942.19744-2-chun-jen.tseng@mediatek.com> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20241108063942.19744-2-chun-jen.tseng@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Il 08/11/24 07:39, Mark Tseng ha scritto: > SoC with CCI architecture should set transition_delay to 10 ms because > cpufreq need to call devfreq notifier in async mode. if delay less than > 10 ms, it may get wrong OPP-level in devfreq passive governor. > This means that MediaTek SoCs can change their CPU frequency once every 10 milliseconds?!?!?! I don't think that's really the case. Besides, are you aware that this will have a *huge* impact on either power consumption or performance? We're going from a bunch of microseconds to *multiple* milliseconds here. Regards, Angelo