Attention is currently required from: Jakub Czapiga, Kapil Porwal, Paul Menzel, Subrata Banik, Tarun Tuli.
Hello Jakub Czapiga, Kapil Porwal, Subrata Banik, Tarun Tuli, build bot (Jenkins),
I'd like you to reexamine a change. Please visit
https://review.coreboot.org/c/coreboot/+/76827?usp=email
to look at the new patch set (#4).
The following approvals got outdated and were removed: Verified+1 by build bot (Jenkins)
Change subject: mb/google/{rex,ovis}: Disable C1-state auto demotion for rex & ovis ......................................................................
mb/google/{rex,ovis}: Disable C1-state auto demotion for rex & ovis
C1-state auto demotion feature allows hardware to determine C1-state as per platform policy. Since platform sets performance policy to balanced from hardware, auto demotion can be disabled without performance impact.
Also, disabling this feature results soc to enter PC2 and lower state in camera preview case and save platform power.
Note: C1 demotion heuristics used EPB parameter to balance between power and performance, i.e. low threshold when EPB is low in-order to get C1 demotion faster and vice-versa. ChromeOS operates at default EPB=0x7 (low EPB) in both AC/DC, so in DC mode it gets more C1 demotion hits than expected (similar to AC mode) and losing power respectively.
BUG=b:286328295 TEST=Code compiles and correct value of c1-state auto demotion is passed to FSP. Also verified PC residency improvement ~10% in camera preview case.
Change-Id: I548e0e5340dec537d05718dd2f4652e10fb36ac0 Signed-off-by: Sukumar Ghorai sukumar.ghorai@intel.com --- M src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb M src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb 2 files changed, 6 insertions(+), 0 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/27/76827/4