Processor Clocking Control (PCC) is an interface between the BIOS and OSPM.
Based on the server workload, OSPM can request what frequency it expects
from a logical CPU, and the BIOS will achieve that frequency transparently.
This patch introduces driver support for PCC. OSPM uses the PCC driver to
communicate with the BIOS via the PCC interface.
There is a Documentation file that provides a link to the PCC
Specification, and also provides a summary of the PCC interface.
Currently, certain HP ProLiant platforms implement the PCC interface. However,
any platform whose BIOS implements the PCC Specification, can utilize this
driver.
V2 --> V1 changes (based on Dominik's suggestions):
- Removed the dependency on CPU_FREQ_TABLE
- "cpufreq_stats" will no longer PANIC. Actually, it will not load anymore
because it is not applicable.
- Removed the sanity check for target frequency in the ->target routine.
NOTE: A patch to sanitize the target frequency requested by "ondemand" is
needed to ensure that the target freq < policy->min.
Can this driver be queued up for the 2.6.33 tree?
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
The e_powersaver driver for VIA's C7 CPU's needs to be marked as
DANGEROUS as it configures the CPU to power states that are out
of specification.
According to Centaur, all systems with C7 and Nano CPU's support
the ACPI p-state method. Thus, the acpi-cpufreq driver should
be used instead.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
powernow-k8 driver should always try to get cpufreq info from ACPI.
Otherwise it will not be able to detect the transition latency correctly
which results in ondemand governor taking a wrong sampling rate which will
then result in sever performance loss.
Let the user not shoot himself in the foot and always compile in ACPI
support for powernow-k8.
This also fixes a wrong message if ACPI_PROCESSOR is compiled as a module and
#ifndef CONFIG_ACPI_PROCESSOR
path is chosen.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
They were long enough set deprecated...
Update Documentation/cpu-freq/users-guide.txt:
The deprecated files listed there seen not to exist for some time anymore
already.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Merge the two Kconfig files to a single file.
Checked using make allmodconfig for x86_64.
No changes in build.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Naga Chumbalkar