The current documentation is incomplete wrt the intel_pstate legacy
internal governors. The confusion comes from the general cpufreq
governors which also use the names performance and powersave. This patch
better differentiates between the two sets of governors and gives an
explanation of how the internal P-state governors behave differently from
one another.
Also fix two minor typos.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: Dirk Brandewie <dirk.j.brandewie@intel.com>
Cc: x86@kernel.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add a sysfs interface to display the total number of supported
pstates. This value is independent of whether turbo has been
enabled or disabled.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch adds "turbo_pct" to the intel_pstate sysfs interface.
turbo_pct will display the percentage of the total supported
pstates that are in the turbo range. This value is independent
of whether turbo has been disabled or not.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add support of Hardware Managed Performance States (HWP) described in Volume 3
section 14.4 of the SDM.
With HWP enbaled intel_pstate will no longer be responsible for selecting P
states for the processor. intel_pstate will continue to register to
the cpufreq core as the scaling driver for CPUs implementing
HWP. In HWP mode intel_pstate provides three functions reporting
frequency to the cpufreq core, support for the set_policy() interface
from the core and maintaining the intel_pstate sysfs interface in
/sys/devices/system/cpu/intel_pstate. User preferences expressed via
the set_policy() interface or the sysfs interface are forwared to the
CPU via the HWP MSR interface.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Update documentation to make the interpretation of the values clearer
Link: https://bugzilla.kernel.org/show_bug.cgi?id=64251
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Intel P-state driver is currently undocumented. Add some
documentation based on the cover-letter sent with the original series.
Cc: Dirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Prarit Bhargava