From e98f033f94f385a9cf498d4e9f2ac1e6198b545a Mon Sep 17 00:00:00 2001
From: Jacob Tanenbaum <jtanenba@redhat.com>
Date: Tue, 1 Dec 2015 17:14:17 +0100
Subject: [PATCH] cpupower: fix how "cpupower frequency-info" interprets
latency
the intel-pstate driver does not support the ondemand governor and does not
have a valid value in
/sys/devices/system/cpu/cpu[x]/cpufreq/cpuinfo_transition_latency. The
intel-pstate driver sets cpuinfo_transition_latency to CPUFREQ_ETERNAL (-1),
the value written into cpuinfo_transition_latency is defind as an unsigned
int so checking the read value against max unsigned int will determine if the
value is valid.
Signed-off-by: Jacob Tanenbaum <jtanenba@redhat.com>
Signed-off-by: Thomas Renninger <trenn@suse.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
tools/power/cpupower/utils/cpufreq-info.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/power/cpupower/utils/cpufreq-info.c b/tools/power/cpupower/utils/cpufreq-info.c
index c13bc8c7c860d..8f3f5bb9c74ef 100644
--- a/tools/power/cpupower/utils/cpufreq-info.c
+++ b/tools/power/cpupower/utils/cpufreq-info.c
@@ -434,8 +434,8 @@ static int get_latency(unsigned int cpu, unsigned int human)
unsigned long latency = cpufreq_get_transition_latency(cpu);
printf(_(" maximum transition latency: "));
- if (!latency) {
- printf(_(" Cannot determine latency.\n"));
+ if (!latency || latency == UINT_MAX) {
+ printf(_(" Cannot determine or is not supported.\n"));
return -EINVAL;
}
--
2.30.2