Messages in this thread Patch in this message | | | From | Erwan Velu <> | Subject | [PATCH] cpufreq: Report if CPU doesn't report boost technologies | Date | Wed, 20 Feb 2019 11:10:17 +0100 |
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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 reporting 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> --- 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..06d32d21dac0 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("CPU doesn't expose boost capabilities\n"); return; + } acpi_cpufreq_driver.set_boost = set_boost; acpi_cpufreq_driver.boost_enabled = boost_state(0); -- 2.20.1
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