From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 7CF4742A96; Sun, 28 Sep 2025 01:59:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759024764; cv=none; b=f+YDKb6hGGBD+K2mfe7VpQODzqVoFUhry95JSqhi1g4cLFK4q2t82o/zs4bwBXUMguhGXGvJf5K1MtWy44Q07dXjp/kR+GUAqMHJpWyO9ZfDNoTvamnJqH6fyTlLIUxlYP4nm76e6uH2duI5t87wb8bo/IV3mtIbUZpO9OuA4Oc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759024764; c=relaxed/simple; bh=N4LPkmwK6smqMMSd9bSdCIg3UiOaiO0ARVFzJHAuoCI=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=ACPJJoxmjVubi73+oB0HwBAomT+JP9VPlSFp9Vh7suPDykkgHuHc9b0GDZfbkuY7EGqpvuhq93jiTy9AotGbQJAxtDaHjXgHNv88LpOSgxXa5wBJ5CVXv3F1T24afOEq6Z7JTv5+84u5GfEYuzHpDESxu9pMeEG1B0xkaMPyn+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com; spf=pass smtp.mailfrom=hisilicon.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hisilicon.com Received: from canpmsgout08.his.huawei.com (unknown [172.19.92.156]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4cZ6ng45S3zJsX5; Sun, 28 Sep 2025 09:54:31 +0800 (CST) Received: from mail.maildlp.com (unknown [172.19.88.163]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4cZ6tk3yZBzmV71; Sun, 28 Sep 2025 09:58:54 +0800 (CST) Received: from kwepemr500004.china.huawei.com (unknown [7.202.195.141]) by mail.maildlp.com (Postfix) with ESMTPS id 32916180044; Sun, 28 Sep 2025 09:59:04 +0800 (CST) Received: from [10.67.121.58] (10.67.121.58) by kwepemr500004.china.huawei.com (7.202.195.141) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sun, 28 Sep 2025 09:59:03 +0800 Message-ID: Date: Sun, 28 Sep 2025 09:59:02 +0800 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/4] cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay To: "Rafael J. Wysocki" , Linux PM CC: Shawn Guo , Qais Yousef , LKML , Viresh Kumar , Pierre Gondois , Mario Limonciello , Linux ACPI References: <5069803.31r3eYUQgx@rafael.j.wysocki> <3406003.44csPzL39Z@rafael.j.wysocki> Content-Language: en-US From: Jie Zhan In-Reply-To: <3406003.44csPzL39Z@rafael.j.wysocki> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To kwepemr500004.china.huawei.com (7.202.195.141) On 9/26/2025 6:19 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a > failure to retrieve the transition latency value from the platform > firmware, the CPPC cpufreq driver will use that value (converted to > microseconds) as the policy transition delay, but it is way too large > for any practical use. > > Address this by making the driver use the cpufreq's default > transition latency value (in microseconds) as the transition delay > if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency(). > > Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us") > Cc: 5.19+ # 5.19 > Signed-off-by: Rafael J. Wysocki > Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Jie Zhan > --- > > v1 -> v3: > * Change the name of the new function (Jie Zhan) > * Add a tag from Mario Limonciello > > --- > drivers/cpufreq/cppc_cpufreq.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-)