Commit d77b8197 authored by Harald Welte's avatar Harald Welte Committed by Dave Jones
Browse files

[CPUFREQ] Enable ACPI PDC handshake for VIA/Centaur CPUs

In commit 0de51088

, we introduced the
use of acpi-cpufreq on VIA/Centaur CPU's by removing a vendor check for
VENDOR_INTEL.  However, as it turns out, at least the Nano CPU's also
need the PDC (processor driver capabilities) handshake in order to
activate the methods required for acpi-cpufreq.

Since arch_acpi_processor_init_pdc() contains another vendor check for
Intel, the PDC is not initialized on VIA CPU's.  The resulting behavior
of a current mainline kernel on such systems is:  acpi-cpufreq
loads and it indicates CPU frequency changes.  However, the CPU stays at
a single frequency

This trivial patch ensures that init_intel_pdc() is called on Intel and
VIA/Centaur CPU's alike.
Signed-off-by: default avatarHarald Welte <>
Signed-off-by: default avatarDave Jones <>
parent a8a8a669
......@@ -79,7 +79,8 @@ void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
struct cpuinfo_x86 *c = &cpu_data(pr->id);
pr->pdc = NULL;
if (c->x86_vendor == X86_VENDOR_INTEL)
if (c->x86_vendor == X86_VENDOR_INTEL ||
c->x86_vendor == X86_VENDOR_CENTAUR)
init_intel_pdc(pr, c);
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