DO NOT ADD FIRMWARE TO THIS DIRECTORY.
======================================
This directory is only here to contain firmware images extracted from old
device drivers which predate the common use of request_firmware().
As we update those drivers to use request_firmware() and keep a clean
separation between code and firmware, we put the extracted firmware
here.
This directory is _NOT_ for adding arbitrary new firmware images. The
place to add those is the separate linux-firmware repository:
git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
That repository contains all these firmware images which have been
extracted from older drivers, as well various new firmware images which
we were never permitted to include in a GPL'd work, but which we _have_
been permitted to redistribute under separate cover.
To submit firmware to that repository, please send either a git binary
diff or preferably a git pull request to:
linux-firmware@kernel.org
and also cc: to related mailing lists.
Your commit should include an update to the WHENCE file clearly
identifying the licence under which the firmware is available, and
that it is redistributable. If the licence is long and involved, it's
permitted to include it in a separate file and refer to it from the
WHENCE file.
And if it were possible, a changelog of the firmware itself.
Ideally, your commit should contain a Signed-Off-By: from someone
authoritative on the licensing of the firmware in question (i.e. from
within the company that owns the code).
WARNING:
=======
Don't send any "CONFIDENTIALITY STATEMENT" in your e-mail, patch or
request. Otherwise your firmware _will never be accepted_.
Maintainers are really busy, so don't expect a prompt reply.
h?h=nds-private-remove'>logtreecommitdiff|
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cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>