[S] Change in coreboot[main]: mb/google/brya/var/nivviks: Enable PCIe Wifi Gpios based on fw_config

[Subrata Banik (Code Review)]

Attention is currently required from: Dinesh Gehlot, Eric Lai, Kapil Porwal, Nick Vaccaro, Poornima Tom, V Sowmya.

Subrata Banik has posted comments on this change by Poornima Tom. ( https://review.coreboot.org/c/coreboot/+/83077?usp=email )

Change subject: mb/google/brya/var/nivviks: Enable PCIe Wifi Gpios based on fw_config
......................................................................

Patch Set 7:

(1 comment)

File src/mainboard/google/brya/variants/nivviks/fw_config.c:

https://review.coreboot.org/c/coreboot/+/83077/comment/ef45ecbd_3aecef9c?usp... :
PS6, Line 103: PAD_CFG_GPO
> Ideally, i think, locking of GPIO becomes relevant, when it is some thing like Write protect signal or something. Also , if we lock this PERST0 signal, then later, if kernel wants to reset the module, this locking will limit it right?
> Also, i looked in the Gale Peak2 EPS doc, but didnot find anything which says that we must lock this reset signal.

please don't mark unless we have an agreement here.

Why would kernel/driver wish to reset the WLAN PERST ? do we have such seq as part of the wlan  enable/disable flow ? if yes then it make sense.

The lock is required for all IPs to block any OS application or entity to wrongly configure the GPIO again.

There is a recent vulnerability reported here malicious software reconfigure GPIO because it was not locked.