Perry Yuan
bedadcfb01
To avoid some new AMD processors use wrong highest perf when amd pstate
driver loaded, this fix will query the highest perf from MSR register
MSR_AMD_CPPC_CAP1 and cppc_acpi interface firstly, then compare with the
highest perf value got by calling amd_get_highest_perf() function.
The lower value will be the correct highest perf we need to use.
Otherwise the CPU max MHz will be incorrect if the
amd_get_highest_perf() did not cover the new process family and model ID.
Like this lscpu info, the max frequency is incorrect.
Vendor ID: AuthenticAMD
Socket(s): 1
Stepping: 2
CPU max MHz: 5410.0000
CPU min MHz: 400.0000
BogoMIPS: 5600.54
Fixes: 3743d55b28 (x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations)
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.