diff options
author | 2015-08-04 12:17:53 -0700 | |
---|---|---|
committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/cpu-freq/amd-powernow.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/cpu-freq/amd-powernow.txt')
-rw-r--r-- | kernel/Documentation/cpu-freq/amd-powernow.txt | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/Documentation/cpu-freq/amd-powernow.txt b/kernel/Documentation/cpu-freq/amd-powernow.txt new file mode 100644 index 000000000..254da155f --- /dev/null +++ b/kernel/Documentation/cpu-freq/amd-powernow.txt @@ -0,0 +1,38 @@ + +PowerNow! and Cool'n'Quiet are AMD names for frequency +management capabilities in AMD processors. As the hardware +implementation changes in new generations of the processors, +there is a different cpu-freq driver for each generation. + +Note that the driver's will not load on the "wrong" hardware, +so it is safe to try each driver in turn when in doubt as to +which is the correct driver. + +Note that the functionality to change frequency (and voltage) +is not available in all processors. The drivers will refuse +to load on processors without this capability. The capability +is detected with the cpuid instruction. + +The drivers use BIOS supplied tables to obtain frequency and +voltage information appropriate for a particular platform. +Frequency transitions will be unavailable if the BIOS does +not supply these tables. + +6th Generation: powernow-k6 + +7th Generation: powernow-k7: Athlon, Duron, Geode. + +8th Generation: powernow-k8: Athlon, Athlon 64, Opteron, Sempron. +Documentation on this functionality in 8th generation processors +is available in the "BIOS and Kernel Developer's Guide", publication +26094, in chapter 9, available for download from www.amd.com. + +BIOS supplied data, for powernow-k7 and for powernow-k8, may be +from either the PSB table or from ACPI objects. The ACPI support +is only available if the kernel config sets CONFIG_ACPI_PROCESSOR. +The powernow-k8 driver will attempt to use ACPI if so configured, +and fall back to PST if that fails. +The powernow-k7 driver will try to use the PSB support first, and +fall back to ACPI if the PSB support fails. A module parameter, +acpi_force, is provided to force ACPI support to be used instead +of PSB support. |