Ran Bi has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/32339 )
Change subject: mediatek/mt8183: Enable RTC eosc calibration feature to save power ......................................................................
Patch Set 2:
(5 comments)
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG Commit Message:
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG@9 PS1, Line 9: shutdown
shuts down […]
In atf code, RTC will switch clock source from dcxo to eosc before real shutdown. So we need to switch it back at next boot.
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG@9 PS1, Line 9: When system shutdown, RTC enable eosc calibration feature to save : power.
… This will reduce the RTC clock source accuracy. […]
At eosc calibration mode, RTC bias is within 63.4ppm which dcxo is within 2ppm.
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG@11 PS1, Line 11: a more accurate one
Which one?
Done
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG@11 PS1, Line 11: boot up
boot
Done
https://review.coreboot.org/#/c/32339/1//COMMIT_MSG@12 PS1, Line 12:
How much power is saved?
This eosc calibration mode saved about 200uA power.