From 1222d527f314c86a3b59a522115d62facc5a7965 Mon Sep 17 00:00:00 2001 From: Erwan Velu Date: Wed, 20 Feb 2019 11:10:17 +0100 Subject: [PATCH] cpufreq: acpi-cpufreq: Report if CPU doesn't support boost technologies There is some rare cases where CPB (and possibly IDA) are missing on processors. This is the case fixed by commit f7f3dc00f612 ("x86/cpu/AMD: Fix erratum 1076 (CPB bit)") and following. In such context, the boost status isn't reported by /sys/devices/system/cpu/cpufreq/boost. This commit is about printing a message to report that the CPU doesn't expose the boost capabilities. This message could help debugging platforms hit by this phenomena. Signed-off-by: Erwan Velu [ rjw: Change the message text somewhat ] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/acpi-cpufreq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index d62fd374d5c7..c72258a44ba4 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -916,8 +916,10 @@ static void __init acpi_cpufreq_boost_init(void) { int ret; - if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) + if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) { + pr_debug("Boost capabilities not present in the processor\n"); return; + } acpi_cpufreq_driver.set_boost = set_boost; acpi_cpufreq_driver.boost_enabled = boost_state(0);