linux-kernel - [PATCH v2 10/13] cpufreq: powernow-k8: Mark 'hi' and 'lo' dummy variables as __always

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Date:   Wed, 15 Jul 2020 09:26:31 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     rjw@...ysocki.net, viresh.kumar@...aro.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org, Lee Jones <lee.jones@...aro.org>,
        Andreas Herrmann <herrmann.der.user@...glemail.com>,
        Dominik Brodowski <linux@...do.de>,
        Pavel Machek <pavel@....cz>,
        Paul Devriendt <paul.devriendt@....com>,
        Mark Langsdorf <mark.langsdorf@....com>
Subject: [PATCH v2 10/13] cpufreq: powernow-k8: Mark 'hi' and 'lo' dummy variables as __always_unused

if we fail to use a variable, even a dummy ones, then the compiler
complains that it is set but not used.  We know this is fine, so we
set them as __always_unused here to let the compiler know.

Fixes the following W=1 kernel build warning(s):

 drivers/cpufreq/powernow-k8.c: In function ‘pending_bit_stuck’:
 drivers/cpufreq/powernow-k8.c:89:10: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]
 89 | u32 lo, hi;
 | ^~
 drivers/cpufreq/powernow-k8.c: In function ‘core_voltage_pre_transition’:
 drivers/cpufreq/powernow-k8.c:285:14: warning: variable ‘lo’ set but not used [-Wunused-but-set-variable]
 285 | u32 maxvid, lo, rvomult = 1;
 | ^~

Cc: Andreas Herrmann <herrmann.der.user@...glemail.com>
Cc: Dominik Brodowski <linux@...do.de>
Cc: Pavel Machek <pavel@....cz>
Cc: Paul Devriendt <paul.devriendt@....com>
Cc: Mark Langsdorf <mark.langsdorf@....com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
 drivers/cpufreq/powernow-k8.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index 3984959eed1d5..0acc9e241cd7d 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -86,7 +86,7 @@ static u32 convert_fid_to_vco_fid(u32 fid)
  */
 static int pending_bit_stuck(void)
 {
-	u32 lo, hi;
+	u32 lo, hi __always_unused;
 
 	rdmsr(MSR_FIDVID_STATUS, lo, hi);
 	return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
@@ -282,7 +282,7 @@ static int core_voltage_pre_transition(struct powernow_k8_data *data,
 {
 	u32 rvosteps = data->rvo;
 	u32 savefid = data->currfid;
-	u32 maxvid, lo, rvomult = 1;
+	u32 maxvid, lo __always_unused, rvomult = 1;
 
 	pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, reqvid 0x%x, rvo 0x%x\n",
 		smp_processor_id(),
-- 
2.25.1