Enable ACPI PDC handshake for VIA/Centaur CPUs
commit37ed9bf8e31377284ca719b823e6794386ee0d5b
authorHarald Welte <HaraldWelte@viatech.com>
Tue, 24 Nov 2009 15:53:00 +0000 (24 16:53 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 8 Dec 2009 18:21:48 +0000 (8 10:21 -0800)
tree0b8f50f98e0d5d3561e889a6fcaadadc3511672d
parent57ce46ef790bc67038322ed59c26f6d8eed9ee61
Enable ACPI PDC handshake for VIA/Centaur CPUs

commit d77b81974521c82fa6fda38dfff1b491dcc62a32 upstream.

In commit 0de51088e6a82bc8413d3ca9e28bbca2788b5b53, 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: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
arch/x86/kernel/acpi/processor.c