From e98f033f94f385a9cf498d4e9f2ac1e6198b545a Mon Sep 17 00:00:00 2001 From: Jacob Tanenbaum 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 Signed-off-by: Thomas Renninger Signed-off-by: Rafael J. Wysocki --- 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 c13bc8c7c860..8f3f5bb9c74e 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; } -- 2.20.1