Tristan Corrick has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/30890 )
Change subject: autoport: Add support for Haswell-LynxPoint platform ......................................................................
Patch Set 2:
(1 comment)
https://review.coreboot.org/#/c/30890/1/util/autoport/lynxpoint.go File util/autoport/lynxpoint.go:
https://review.coreboot.org/#/c/30890/1/util/autoport/lynxpoint.go@272 PS1, Line 272: RestoreDIRRoute(sb, "D31IR", uint16(inteltool.RCBA[0x3140])) : RestoreDIRRoute(sb, "D29IR", uint16(inteltool.RCBA[0x3144])) : RestoreDIRRoute(sb, "D28IR", uint16(inteltool.RCBA[0x3146])) : RestoreDIRRoute(sb, "D27IR", uint16(inteltool.RCBA[0x3148])) : RestoreDIRRoute(sb, "D26IR", uint16(inteltool.RCBA[0x314c])) : RestoreDIRRoute(sb, "D25IR", uint16(inteltool.RCBA[0x3150])) : RestoreDIRRoute(sb, "D22IR", uint16(inteltool.RCBA[0x315c])) : RestoreDIRRoute(sb, "D20IR", uint16(inteltool.RCBA[0x3160]))
I see google/slippy/variants/peppy also writes DxxIP registers. I still don't know which are needed.
DxxIR and DxxIP are only useful to support legacy interrupt routing. I'm not aware of a major, mainstream OS that uses legacy interrupt routing by default. It would be fine to leave these registers at their reset defaults. As far as I know, legacy interrupt routing should still work in that case, but the interrupts might not be balanced very well.
Lynx Point could benefit from making this config PCH-specific instead of board-specific, as was done in commit 33b535f15ded for earlier PCHs.