From: Erwan Velu erwanaliasr1@gmail.com
[ Upstream commit 1222d527f314c86a3b59a522115d62facc5a7965 ]
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 e.velu@criteo.com [ rjw: Change the message text somewhat ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b61f4ec43e06..aca30f45172e 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -911,8 +911,10 @@ 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);