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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 BA091C433DB for ; Mon, 22 Mar 2021 03:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 901B561931 for ; Mon, 22 Mar 2021 03:18:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229761AbhCVDRv (ORCPT ); Sun, 21 Mar 2021 23:17:51 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:14415 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbhCVDRa (ORCPT ); Sun, 21 Mar 2021 23:17:30 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4F3flX3hMlzkd7Y; Mon, 22 Mar 2021 11:15:52 +0800 (CST) Received: from vm-Yoda-Ubuntu1804.huawei.com (10.67.174.59) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Mon, 22 Mar 2021 11:17:20 +0800 From: Xu Yihang To: , , , , , , CC: , , , , Subject: [PATCH -next] x86: Fix unused variable 'msr_val' warning Date: Mon, 22 Mar 2021 11:17:13 +0800 Message-ID: <20210322031713.23853-1-xuyihang@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.174.59] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fixes the following W=1 kernel build warning(s): arch/x86/hyperv/hv_spinlock.c:28:16: warning: variable ‘msr_val’ set but not used [-Wunused-but-set-variable] unsigned long msr_val; As Hypervisor Top-Level Functional Specification states in chapter 7.5 Virtual Processor Idle Sleep State, "A partition which possesses the AccessGuestIdleMsr privilege (refer to section 4.2.2) may trigger entry into the virtual processor idle sleep state through a read to the hypervisor-defined MSR HV_X64_MSR_GUEST_IDLE". That means only a read is necessary, msr_val is not uesed, so __maybe_unused should be added. Reference: https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs Reported-by: Hulk Robot Signed-off-by: Xu Yihang --- arch/x86/hyperv/hv_spinlock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c index f3270c1fc48c..67bc15c7752a 100644 --- a/arch/x86/hyperv/hv_spinlock.c +++ b/arch/x86/hyperv/hv_spinlock.c @@ -25,7 +25,7 @@ static void hv_qlock_kick(int cpu) static void hv_qlock_wait(u8 *byte, u8 val) { - unsigned long msr_val; + unsigned long msr_val __maybe_unused; unsigned long flags; if (in_nmi()) -- 2.17.1