Michael Niewöhner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/35516 )
Change subject: device/pci: Ensure full 16-bit VGA port i/o decoding ......................................................................
Patch Set 1:
(1 comment)
Patch Set 1: Code-Review-1
Dug a little into the chipset support for historical Intel in the tree: Older ICHs implement the bit r/w but mention to ignore it anyway, because everything goes to PCI. So that should be fine.
440BX doesn't seem to know it, though :-/ So this can't go in as is. I'm open for suggestions. What should we do if 16-bit decode isn't possible? Restrict all i/o to 10 bits? That could brick... Hmmmm, just warn about it? Instead of skipping the device?
I really don't like to reserve the VGA resources 64 times, could do that, though.
https://review.coreboot.org/c/coreboot/+/35516/1/src/include/device/pci_def.... File src/include/device/pci_def.h:
https://review.coreboot.org/c/coreboot/+/35516/1/src/include/device/pci_def.... PS1, Line 174: #define PCI_CB_BRIDGE_CTL_VGA 0x08
Not sure what 0x10 is with cardbus. […]
cardbus matches, see spec