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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92FFAC433EF for ; Mon, 1 Nov 2021 12:50:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 786D560F70 for ; Mon, 1 Nov 2021 12:50:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232520AbhKAMw4 (ORCPT ); Mon, 1 Nov 2021 08:52:56 -0400 Received: from mga07.intel.com ([134.134.136.100]:54909 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232533AbhKAMwz (ORCPT ); Mon, 1 Nov 2021 08:52:55 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10154"; a="294462474" X-IronPort-AV: E=Sophos;i="5.87,199,1631602800"; d="scan'208";a="294462474" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2021 05:50:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,199,1631602800"; d="scan'208";a="488641282" Received: from unknown (HELO linux-youquan.bj.intel.com) ([10.238.155.175]) by orsmga007.jf.intel.com with ESMTP; 01 Nov 2021 05:50:20 -0700 From: Youquan Song To: linux-pm@vger.kernel.org, rafael.j.wysocki@intel.com Cc: youquan.song@intel.com Subject: [PATCH] PM/QoS: resume latency 0 should be not latency allowed Date: Mon, 1 Nov 2021 19:36:58 +0800 Message-Id: <1635766618-24732-1-git-send-email-youquan.song@intel.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org ICX and more recent Intel CPU has C1 exit_latency equal 1 in intel_idle driver, There are PM QoS interfaces: global /dev/cpu_dma_latency and per-device latency constraints. per-CPU set pm_qos_resume_latency_us to limit single CPU entery into deepest C-state. When it is required to disable entry into even C1, we need to set "0" to /sys pm_qos_resume_latency_us, but "0" of pm_qos_resume_latency_us is redefined to no constraint now. so this patch set "0" back to original meaning "no latency at all". Signed-off-by: Youquan Song --- drivers/base/power/sysfs.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index a1474fb67db9..b4bd67e6f440 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -214,10 +214,8 @@ static ssize_t pm_qos_resume_latency_us_show(struct device *dev, { s32 value = dev_pm_qos_requested_resume_latency(dev); - if (value == 0) - return sysfs_emit(buf, "n/a\n"); if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) - value = 0; + return sysfs_emit(buf, "no constraint\n"); return sysfs_emit(buf, "%d\n", value); } @@ -237,10 +235,8 @@ static ssize_t pm_qos_resume_latency_us_store(struct device *dev, if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) return -EINVAL; - if (value == 0) - value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; } else if (sysfs_streq(buf, "n/a")) { - value = 0; + value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; } else { return -EINVAL; } -- 2.27.0