mikeb mikeb has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/31448 )
Change subject: src/device/pci: Add support for discrete VGA initialization and OpROM loading ......................................................................
Patch Set 1:
(1 comment)
Patch Set 1:
https://review.coreboot.org/c/coreboot/+/31502 should fix the issue on dual gpu systems.
See my comment below, also today I tested your [WIP] patch, and - in its' current state - it does not seem to affect the discrete GPU : if I do VFCT filling for integated GPU like you suggested, the discrete GPU does not work , but if I do VFCT for discrete GPU instead - both integrated and discrete GPUs are working ; and these outcomes are happening this way both without and with your patch merged.
https://review.coreboot.org/#/c/31448/1/src/device/pci_rom.c File src/device/pci_rom.c:
https://review.coreboot.org/#/c/31448/1/src/device/pci_rom.c@274 PS1, Line 274: /* Write ACPI VFCT only for Discrete VGA. */
looking at the kernel source: […]
Today I tried following your "VFCT should be used for the integrated GPU in dual graphics systems" advice above and enabled VFCT filling for integrated GPU only in both cases, but sadly the discrete GPU/driver failed to initialize and I got the errors in kernel log which you could see in a message to Nico above. So I still need to do VFCT filling for discrete GPU instead of integrated - because otherwise it does not work.