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=-14.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 A1514C43466 for ; Mon, 21 Sep 2020 16:39:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65E8423998 for ; Mon, 21 Sep 2020 16:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706351; bh=s0Mo5u+brxlYU38Nh/VQSLjrk4n3pEAdmA+E2c66PFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LXXy23OgiEIZcvMbN9RhrOJ4HVlr8TS1aeHc7A1sF34EJYSp1VMs84mfg776m06Lt ZFjVkc5dN1VqS5w6UKZx1XM1X6BKo2fYtzgKgMbR2cJRC2rC0FD31fzPwGPgP22e5m rcRbzqw+VXLMTFHR1wyx2cy+onrjXtxRlLCpYlwU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729220AbgIUQjF (ORCPT ); Mon, 21 Sep 2020 12:39:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:40526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729215AbgIUQi7 (ORCPT ); Mon, 21 Sep 2020 12:38:59 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ADD49239D0; Mon, 21 Sep 2020 16:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706339; bh=s0Mo5u+brxlYU38Nh/VQSLjrk4n3pEAdmA+E2c66PFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AV4YstBitza6ozJhQ2etu3oMYygNsdRrJqjFsn90ASYwUgVuws7LacZDxwz7CikJ/ gxtQHut08JDlR5h5s10LiOPw7ZC/bPv8AUJmNPaNwJIct8ChH+ZqkmuyZRsCATBnIn Zixou0fw3hqKX7ScVGdONSIZ18S7JLVodiq6IE9w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Rafael J. Wysocki" , Srinivas Pandruvada , Sasha Levin Subject: [PATCH 4.14 20/94] cpufreq: intel_pstate: Refuse to turn off with HWP enabled Date: Mon, 21 Sep 2020 18:27:07 +0200 Message-Id: <20200921162036.476048041@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162035.541285330@linuxfoundation.org> References: <20200921162035.541285330@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 5c41dc9aaa46d..be1a7bb0b4011 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2098,9 +2098,15 @@ 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