Hello Felix Singer, Matt Delco, Nico Huber, Paul Menzel, Patrick Rudolph,
I'd like you to reexamine a change. Please visit
https://review.coreboot.org/c/coreboot/+/44137
to look at the new patch set (#2).
Change subject: soc/intel/skylake: acpi: drop HWP's dependency on EIST ......................................................................
soc/intel/skylake: acpi: drop HWP's dependency on EIST
Enhanced Intel SpeedStep Technology (EIST) and Intel Speed Shift Technology (ISST) - also know as HWP - are two independent mechanisms for controlling voltage and frequency based on performance hints.
When HWP is enabled, it overrides the software-based EIST. It does not depend on EIST, though, but can be enabled on it's own.
Break up that currently exisiting dependency in ACPI generation code.
It was tested that HWP can be enabled and gets used by the Linux pstate cpufreq driver. With HWP disabled, the frequency does not decrease, even not in powersave mode. After enabling HWP the frequency changed in relation to the current workload.
Change-Id: I93d888ddce7b54e91b54e5b4fdd4d9cf16630eda Signed-off-by: Michael Niewöhner foss@mniewoehner.de --- M src/soc/intel/skylake/acpi.c 1 file changed, 5 insertions(+), 3 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/37/44137/2