[coreboot-gerrit] [S] Change in coreboot[master]: mb/google/myst: Enable fingerprint on UART

[Tim Van Patten (Code Review)]

Attention is currently required from: Eric Lai, Jon Murphy, Karthik Ramasubramanian, Paul Menzel.

Tim Van Patten has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/75629?usp=email )

Change subject: mb/google/myst: Enable fingerprint on UART
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Patch Set 3:

(1 comment)

File src/mainboard/google/myst/variants/baseboard/gpio.c:

https://review.coreboot.org/c/coreboot/+/75629/comment/c620141e_d80db422 :
PS3, Line 71: 	PAD_GPO(GPIO_40, LOW),
Is there a HW spec requirement for how long the line must stay asserted?

My understanding is that we use `generic.reset_delay_ms` in the device tree to explicitly control how long we keep the reset signal toggled during boot to satisfy any HW requirements. Otherwise, there's no guarantee that the line is asserted long enough in both the cold boot and cold reset cases.