From patchwork Mon Aug 19 03:51:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jie Zhan X-Patchwork-Id: 821235 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (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 44E6813D2BE; Mon, 19 Aug 2024 03:57:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724039852; cv=none; b=ehR+fapHH7wxhisox/tTH/OaNzPLGmDOb1gAIQ689q77lsWwwkiMjNknCGTEzO9nD5YuAR4WTQrxsSXf8jS9I36/iNYk2BH0K6QQBqS8njW/5D9cpoyB5ePriZH+s49SU1S9fuUgvxyH14GuFPijze+hEgNFSRcAsSG128gMyRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724039852; c=relaxed/simple; bh=MeoyMJD/FG2lYYutmTBc5FDnGdYbT1KGGBnk1Gw5ieA=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=JmK8go8TBeGddfhsWeh/ECc3FvSwE+7kADXWIn55n8dvUqHXpMYfLR5WoiTYefvZQWGN5Qr+cmilC3ygiEolaeaqW8ZFwBwzbgoiiZ70dLQQzlvn/lpbXuw/q1Cm/T3bUYzeUOQTnRmIynnXa3UonU+NaldvIlNXv/8fKFIDbdU= 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=45.249.212.188 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 mail.maildlp.com (unknown [172.19.88.194]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4WnJfk17WfzpTF8; Mon, 19 Aug 2024 11:55:58 +0800 (CST) Received: from dggpeml500019.china.huawei.com (unknown [7.185.36.137]) by mail.maildlp.com (Postfix) with ESMTPS id 16542140159; Mon, 19 Aug 2024 11:57:26 +0800 (CST) Received: from localhost.localdomain (10.90.30.45) by dggpeml500019.china.huawei.com (7.185.36.137) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Mon, 19 Aug 2024 11:57:25 +0800 From: Jie Zhan To: , CC: , , , , , , , , Subject: [PATCH] cpufreq: CPPC: Return desired perf in ->get() if feedback counters are 0 Date: Mon, 19 Aug 2024 11:51:47 +0800 Message-ID: <20240819035147.2239767-1-zhanjie9@hisilicon.com> X-Mailer: git-send-email 2.30.0 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500019.china.huawei.com (7.185.36.137) The CPPC performance feedback counters could return 0 when the target cpu is in a deep idle state (e.g. powered off) and those counters are not powered. cppc_cpufreq_get_rate() returns 0 in this case, triggering two problems: 1. cpufreq_online() gets a false error and doesn't generate a cpufreq policy, which happens in cpufreq_add_dev() when a new cpu device is added. 2. 'cpuinfo_cur_freq' shows '' Don't take it as an error and return the frequency corresponding to the desired perf when the feedback counters are 0. Fixes: 6a4fec4f6d30 ("cpufreq: cppc: cppc_cpufreq_get_rate() returns zero in all error cases.") Signed-off-by: Jie Zhan --- drivers/cpufreq/cppc_cpufreq.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index bafa32dd375d..1c5eb12c1a5a 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -748,18 +748,25 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu) ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0); if (ret) - return 0; + goto out_err; udelay(2); /* 2usec delay between sampling */ ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1); if (ret) - return 0; + goto out_err; delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0, &fb_ctrs_t1); return cppc_perf_to_khz(&cpu_data->perf_caps, delivered_perf); + +out_err: + if (ret == -EFAULT) + return cppc_perf_to_khz(&cpu_data->perf_caps, + cpu_data->perf_ctrls.desired_perf); + + return 0; } static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)