[PATCH 08/13] cpufreq: acpi-cpufreq: Take 'dummy' principle one stage further

Lee Jones
2020-07-14T14:53:59Z

If we fail to use a variable, even a 'dummy' one, then the compiler
complains that it is set but not used. We know this is fine, so we
set it to its own value here.

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

drivers/cpufreq/acpi-cpufreq.c: In function ‘cpu_freq_read_intel’:
drivers/cpufreq/acpi-cpufreq.c:247:11: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable]
drivers/cpufreq/acpi-cpufreq.c: In function ‘cpu_freq_read_amd’:
drivers/cpufreq/acpi-cpufreq.c:265:11: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable]

Cc: Andy Grover <andrew.grover@intel.com>
Cc: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
Cc: Dominik Brodowski <linux@brodo.de>
Cc: Denis Sadykov <denis.m.sadykov@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/cpufreq/acpi-cpufreq.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 429e5a36c08a9..d38a693b48e03 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -247,6 +247,7 @@ static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
u32 val, dummy;

rdmsr(MSR_IA32_PERF_CTL, val, dummy);
+ dummy &= dummy; /* Silence set but not used warning */
return val;
}

@@ -264,6 +265,7 @@ static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
u32 val, dummy;

rdmsr(MSR_AMD_PERF_CTL, val, dummy);
+ dummy &= dummy; /* Silence set but not used warning */
return val;
}

--
2.25.1