64fbe39232
commit 8e47363588377e1bdb65e2b020b409cfb44dd260 upstream.
The powerclamp cooling device cur_state shows actual idle observed by
package C-state idle counters. But the implementation is not sufficient
for multi package or multi die system. The cur_state value is incorrect.
On these systems, these counters must be read from each package/die and
somehow aggregate them. But there is no good method for aggregation.
It was not a problem when explicit CPU model addition was required to
enable intel powerclamp. In this way certain CPU models could have
been avoided. But with the removal of CPU model check with the
availability of Package C-state counters, the driver is loaded on most
of the recent systems.
For multi package/die systems, just show the actual target idle state,
the system is trying to achieve. In powerclamp this is the user set
state minus one.
Also there is no use of starting a worker thread for polling package
C-state counters and applying any compensation for multiple package
or multiple die systems.
Fixes: b721ca0d1927 ("thermal/powerclamp: remove cpu whitelist")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.