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| author |   Dirk Brandewie <dirk.j.brandewie@intel.com> | 2014-10-13 08:37:44 -0700 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-10-23 23:00:00 +0200 |
| commit | d022a65ed2473fac4a600e3424503dc571160a3e (patch) | |
| tree | 6ff152f13f0ce8918e97ecd968fd7d3fabf13fcf /drivers/acpi/device_pm.c | |
| parent | intel_pstate: Fix BYT frequency reporting (diff) | |
| download | linux-dev-d022a65ed2473fac4a600e3424503dc571160a3e.tar.xz linux-dev-d022a65ed2473fac4a600e3424503dc571160a3e.zip | |
intel_pstate: Correct BYT VID values.
Using a VID value that is not high enough for the requested P state can
cause machine checks. Add a ceiling function to ensure calulated VIDs
with fractional values are set to the next highest integer VID value.
The algorythm for calculating the non-trubo VID from the BIOS writers
guide is:
vid_ratio = (vid_max - vid_min) / (max_pstate - min_pstate)
vid = ceiling(vid_min + (req_pstate - min_pstate) * vid_ratio)
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/device_pm.c')
0 files changed, 0 insertions, 0 deletions