David Hendricks has posted comments on this change. ( https://review.coreboot.org/22020 )
Change subject: spi25: Add native 4BA support ......................................................................
Patch Set 1: -Code-Review
(1 comment)
The code here looks fine, I just want to check my understanding of how you're deciding whether to use 4BA native instructions or extended address mode. As you're probably already aware, some chips support one but not the other, so we need to be a little careful.
From what I've seen, it's safer to use native 4BA instructions when they're available since they should work no matter what mode the chip is in.
Also, we should consider how we might override the default behavior in case the programmer can only operate in a particular mode (I'm thinking Intel chipsets and Dediprog programmers).
https://review.coreboot.org/#/c/22020/1/spi25.c File spi25.c:
https://review.coreboot.org/#/c/22020/1/spi25.c@363 PS1, Line 363: flash->address_high_byte = addr_high; The follow-up patch seems to use native 4BA instructions for read and write regardless of what you do here.