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 02E35C43461 for ; Mon, 7 Sep 2020 16:47:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A4DB208C7 for ; Mon, 7 Sep 2020 16:47:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599497256; bh=Wvu8NGaWM525ZYiB8wDCt6ajdHm2w09PCo61MkOKhLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V8dr66IxOcd73p90+1AecUikOtfvHfncV7lifO7eLr5iCSG2y8ySkJjBG6N6Onp4x Efuuz+BIF5fW8L8MtzcZx4kuJW+4PdZQrx2R2AH4qqhN3oXMVZeAat/oYVdfR+C13Q Zh6VWGBlMQSH6qCsx1a5GnupLPOjQnYDSDC/ml4c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730917AbgIGQrc (ORCPT ); Mon, 7 Sep 2020 12:47:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:49218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730815AbgIGQfU (ORCPT ); Mon, 7 Sep 2020 12:35:20 -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 E6D8721D94; Mon, 7 Sep 2020 16:35:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599496519; bh=Wvu8NGaWM525ZYiB8wDCt6ajdHm2w09PCo61MkOKhLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aSX6PHErAvmcusnqoaeg2dmdxVuqJYswp8tETIme3Wckk6Kgm8W8ywYkxV6exgKq8 yOFH6TfpNb8UR2dyJovoY2WSIG73Z2BMq4X0bFbR6LhCSyyYEigxzECDWETuUsFra9 VDZCJbkrpNeikmVM29eMKDaVbldQo7yx7veZSJFI= 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 4.14 14/17] cpufreq: intel_pstate: Refuse to turn off with HWP enabled Date: Mon, 7 Sep 2020 12:34:57 -0400 Message-Id: <20200907163500.1281543-14-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200907163500.1281543-1-sashal@kernel.org> References: <20200907163500.1281543-1-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 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