227ed18f45
turbostat prints the abnormal SYS%LPI across suspend-to-idle: SYS%LPI = 114479815993277.50 This is reproduced by: Run a freeze cycle, e.g. "sleepgraph -m freeze -rtcwake 15". Then do a reboot. After boot up, launch the suspend-idle-idle and check the SYS%LPI field. The slp_so residence counter is in LPIT table, and BIOS does not clears this register across reset. The PMC expects the OS to calculate the LPI residency based on the delta. However, there is an firmware issue that the LPIT gets cleared to 0 during the second suspend to idle after the reboot, which brings negative delta value. [lenb: updated to print "neg" upon this BIOS failure] Reported-by: Todd Brandt <todd.e.brandt@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Len Brown <len.brown@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.