acpi-cpufreq: Add compatibility for legacy AMD cpb sysfs knob
The powernow-k8 driver supported a sysfs knob called "cpb", which was
instantiated per CPU, but actually acted globally for the whole
system. To keep some compatibility with this feature, we re-introduce
this behavior here, but:
a) only enable it on AMD CPUs and
b) protect it with a Kconfig switch
I'd like to consider this feature obsolete. Lets keep it around for
some kernel versions and then phase it out.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index b36ca1f..934854a 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -33,6 +33,18 @@
If in doubt, say N.
+config X86_ACPI_CPUFREQ_CPB
+ default y
+ bool "Legacy cpb sysfs knob support for AMD CPUs"
+ depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
+ help
+ The powernow-k8 driver used to provide a sysfs knob called "cpb"
+ to disable the Core Performance Boosting feature of AMD CPUs. This
+ file has now been superseeded by the more generic "boost" entry.
+
+ By enabling this option the acpi_cpufreq driver provides the old
+ entry in addition to the new boost ones, for compatibility reasons.
+
config ELAN_CPUFREQ
tristate "AMD Elan SC400 and SC410"
select CPU_FREQ_TABLE