718be4aaf3
It turns out that there is a bit in the _CST for Intel FFH C3 that tells the OS if we should be checking BM_STS or not. Linux has been unconditionally checking BM_STS. If the chip-set is configured to enable BM_STS, it can retard or completely prevent entry into deep C-states -- as illustrated by turbostat: http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/ ref: Intel Processor Vendor-Specific ACPI Interface Specification table 4 "_CST FFH GAS Field Encoding" Bit 1: Set to 1 if OSPM should use Bus Master avoidance for this C-state https://bugzilla.kernel.org/show_bug.cgi?id=15886 Signed-off-by: Len Brown <len.brown@intel.com> |
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| .. | ||
| platform | ||
| acexcep.h | ||
| acnames.h | ||
| acoutput.h | ||
| acpi.h | ||
| acpi_bus.h | ||
| acpi_drivers.h | ||
| acpi_numa.h | ||
| acpiosxf.h | ||
| acpixf.h | ||
| acrestyp.h | ||
| actbl.h | ||
| actbl1.h | ||
| actbl2.h | ||
| actypes.h | ||
| apei.h | ||
| atomicio.h | ||
| button.h | ||
| container.h | ||
| hed.h | ||
| pdc_intel.h | ||
| processor.h | ||
| reboot.h | ||
| video.h | ||