soc/intel/tigerlake: Disable C1 C-state Demotion

Disable C1 C-state auto demotion to decrease SoC power usage.

When set, processor will conditionally demote C3/C6/C7 requests
to C1 based on uncore auto-demote information.

BUG=b:161215906
TEST=Measure and confirm SoC power usage reduction for key use cases
 eg 'Google Meets video call'

Measured on instrumented boards for Volteer EVT and Delbin.

Below measurements for Volteer:

Google meets with 720p 	w/ auto-demotion   w/o auto-demotion
System Power 	        13.14W	              9.4W
SOC Power 	         7.9W	              5.4W

Signed-off-by: Ravi Sarawadi <ravishankar.sarawadi@intel.com>
Signed-off-by: Shweta Malik <shweta.malik@intel.com>
Change-Id: I649cafbaf03917d76521aa5f76ec58d218e1a1b1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46438
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

0 files changed, 0 insertions, 0 deletions