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 X-Spam-Level: X-Spam-Status: No, score=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0272DC433E2 for ; Mon, 7 Sep 2020 16:38:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8E1C21D1A for ; Mon, 7 Sep 2020 16:38:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599496731; bh=kRGI6MiUzQgiO4GjNB5LCtBaozVobZUa1XRfOrzTVtE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gzOqOK5LUZwQmJTZ7yDvcSv5QavBTGLR5Jq53biHzHqg3m2xjyBnSCl72aqka8dAm /f8HeH6hXW6AhKPqLQ8coVnR1N845Nw/Ez9aMRFma7N/q6LXTBBasrsHNCeDV16b+T kVCLTP/PJdPgYDVejcCsdcEsS+JMfgYTR9OUlqBk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730495AbgIGQiu (ORCPT ); Mon, 7 Sep 2020 12:38:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:48602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730773AbgIGQew (ORCPT ); Mon, 7 Sep 2020 12:34:52 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FE8321D90; Mon, 7 Sep 2020 16:34:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599496492; bh=kRGI6MiUzQgiO4GjNB5LCtBaozVobZUa1XRfOrzTVtE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=okRBvkJ4ZC45CGalQHOdwmoNcoxWYiD/jQkUXYqmVJ8dBnX4w8n0RpgKUz5uX5YzT Eq2AGOQo0xaapfwxkcmF7g+4aob2uPSQdv+HcSJl0mXNm6lVgB391EA+3boaKpep4x E3BkkkHOqHsx/UToy5QpjQkMohx+DAwBpIDkYwDo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Rafael J. Wysocki" , Srinivas Pandruvada , Sasha Levin , linux-pm@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 20/26] cpufreq: intel_pstate: Refuse to turn off with HWP enabled Date: Mon, 7 Sep 2020 12:34:20 -0400 Message-Id: <20200907163426.1281284-20-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200907163426.1281284-1-sashal@kernel.org> References: <20200907163426.1281284-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Rafael J. Wysocki" [ Upstream commit 43298db3009f06fe5c69e1ca8b6cfc2565772fa1 ] After commit f6ebbcf08f37 ("cpufreq: intel_pstate: Implement passive mode with HWP enabled") it is possible to change the driver status to "off" via sysfs with HWP enabled, which effectively causes the driver to unregister itself, but HWP remains active and it forces the minimum performance, so even if another cpufreq driver is loaded, it will not be able to control the CPU frequency. For this reason, make the driver refuse to change the status to "off" with HWP enabled. Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada Signed-off-by: Sasha Levin --- drivers/cpufreq/intel_pstate.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 99166000ffb77..8fa22aa2ac65b 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2325,9 +2325,15 @@ static int intel_pstate_update_status(const char *buf, size_t size) { int ret; - if (size == 3 && !strncmp(buf, "off", size)) - return intel_pstate_driver ? - intel_pstate_unregister_driver() : -EINVAL; + if (size == 3 && !strncmp(buf, "off", size)) { + if (!intel_pstate_driver) + return -EINVAL; + + if (hwp_active) + return -EBUSY; + + return intel_pstate_unregister_driver(); + } if (size == 6 && !strncmp(buf, "active", size)) { if (intel_pstate_driver) { -- 2.25.1