linux-kernel - [PATCH -next] x86: Fix unused variable 'hi'

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Message-ID: <20210323025013.191533-1-xuyihang@huawei.com>
Date:   Tue, 23 Mar 2021 10:50:13 +0800
From:   Xu Yihang <xuyihang@...wei.com>
To:     <kys@...rosoft.com>, <haiyangz@...rosoft.com>,
        <sthemmin@...rosoft.com>, <wei.liu@...nel.org>,
        <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
        <x86@...nel.org>, <hpa@...or.com>
CC:     <linux-hyperv@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <xuyihang@...wei.com>, <johnny.chenyi@...wei.com>
Subject: [PATCH -next] x86: Fix unused variable 'hi'

Fixes the following W=1 kernel build warning(s):
arch/x86/hyperv/hv_apic.c:58:15: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]

Compiled with CONFIG_HYPERV enabled:
make allmodconfig ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-
make W=1 arch/x86/hyperv/hv_apic.o ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-

HV_X64_MSR_EOI stores on bit 31:0 and HV_X64_MSR_TPR stores in bit 7:0, which means higher
32 bits are not really used, therefore  potentially cast to void in order to silent this warning.

Reported-by: Hulk Robot <hulkci@...wei.com>
Signed-off-by: Xu Yihang <xuyihang@...wei.com>
---
 arch/x86/hyperv/hv_apic.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 284e73661a18..a8b639498033 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -60,9 +60,11 @@ static u32 hv_apic_read(u32 reg)
 	switch (reg) {
 	case APIC_EOI:
 		rdmsr(HV_X64_MSR_EOI, reg_val, hi);
+		(void) hi;
 		return reg_val;
 	case APIC_TASKPRI:
 		rdmsr(HV_X64_MSR_TPR, reg_val, hi);
+		(void) hi;
 		return reg_val;
 
 	default:
-- 
2.17.1