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 54170C2BB84 for ; Mon, 7 Sep 2020 16:55:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F0F8207DE for ; Mon, 7 Sep 2020 16:55:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599497707; bh=VZJnraZM6yoNBszRUhaP+fnBHLTcAb3TgTZWtLcSQ6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JwPQMKJBlY5SdfXe+NOlkym7oQDmTstD6DjHK2n7tR6XdbqWOGSVUgCrZclQR2ZOj xRdxliRBHkMv4QQP3qgmq4E92xh5sT52YtwW27ZvSOAN6hD5zctowQ/ciPFBkZa6OB 8RxVftDVtdsosKhT308kSJm8a96YyNfuLdmuwXRE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731181AbgIGQzF (ORCPT ); Mon, 7 Sep 2020 12:55:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:48164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730749AbgIGQeR (ORCPT ); Mon, 7 Sep 2020 12:34:17 -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 BB68121D82; Mon, 7 Sep 2020 16:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599496454; bh=VZJnraZM6yoNBszRUhaP+fnBHLTcAb3TgTZWtLcSQ6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xUm5ui/M9PL0A7FbaknGP2dK8yMBba2/tJ5xa0Yq0fxLiZQSolWUbPUuX2Fbbp8nD KwVYVTgSCH+l+xiDV8NJJG6fmgGfUDiUSdcJR/lWavdacz5zhD8Qo//Ik8vh+oXsvn U+ftZNrj3QKmIYjzvSARzkiOWeDGmMqCzjTHCh+M= 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 5.4 35/43] cpufreq: intel_pstate: Refuse to turn off with HWP enabled Date: Mon, 7 Sep 2020 12:33:21 -0400 Message-Id: <20200907163329.1280888-35-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200907163329.1280888-1-sashal@kernel.org> References: <20200907163329.1280888-1-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 927eb3fd23660..5bad88f6ddd59 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2533,9 +2533,15 @@ 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