Attention is currently required from: Hung-Te Lin, Paul Menzel, Yu-Ping Wu. Rex-BC Chen has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62893 )
Change subject: mb/google/corsola: Revise power-on sequence of PS8640 ......................................................................
Patch Set 6:
(5 comments)
Commit Message:
https://review.coreboot.org/c/coreboot/+/62893/comment/f5b5d2cc_9092c580 PS5, Line 10: do
does
Done
https://review.coreboot.org/c/coreboot/+/62893/comment/68404bcd_2e2c3a0f PS5, Line 9: The power-on sequence of PS8640 needs to be modified because the : waveform of power-on sequence do not meet the spec of PS8640.
Is there a user noticeable display issue?
no, just not meet power-on spec measured by oscilloscope.
https://review.coreboot.org/c/coreboot/+/62893/comment/968402ab_76fbafac PS5, Line 10: waveform of power-on sequence
How do you measure it? […]
Done
https://review.coreboot.org/c/coreboot/+/62893/comment/b093a5e8_ee4dc024 PS5, Line 16: TEST=show fw display normally in krabby.
Please document, that/if boot time is now 110 ms longer. […]
In normal boot flow, display will be disable, and we won't take that 110ms. I also add the description in commit message.
https://review.coreboot.org/c/coreboot/+/62893/comment/d447db1c_85434b68 PS5, Line 17: result of waveform meets the spec.
As the datasheet is not publicly accessible, what does it look like?
I add power-on sequence in commit message: - set VDD12 to be 1.2V - set VDD33 to be 3.3V - pull hign PD# - pull down RST# - delay 2ms - pull high RST# - delay more than 50ms (55ms for margin) - pull down RST# - delay more than 50ms (55ms for margin) - pull high RST#