On Mon, Mar 18, 2024 at 3:52 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > On Mon, Mar 18, 2024 at 12:06 PM Kurt Kartaltepe <kkartaltepe@xxxxxxxxx> wrote: > > > > On Mon, Mar 18, 2024 at 8:42 AM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > > > > > On Mon, Mar 18, 2024 at 10:19 AM Kurt Kartaltepe <kkartaltepe@xxxxxxxxx> wrote: > > > > > > > > On Mon, Mar 18, 2024 at 6:37 AM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > > > > > > > > > On Mon, Mar 18, 2024 at 4:47 AM Kurt Kartaltepe <kkartaltepe@xxxxxxxxx> wrote: > > > > > > > > > > > > These checks prevent using amdgpu with the pcie=assign-busses parameter > > > > > > which will re-address devices from their acpi values. > > > > > > > > > > > > Signed-off-by: Kurt Kartaltepe <kkartaltepe@xxxxxxxxx> > > > > > > > > > > This will likely break multi-GPU functionality. The BDF values are > > > > > how the sbios/driver differentiates between the VFCT images. If you > > > > > have multiple GPUs in the system, the driver won't be able to figure > > > > > out which one goes with which GPU an you may end up assigning the > > > > > wrong image to the wrong device. > > > > > > > > > > Alex > > > > > > > > The vendor and device portions must be correct in the existing > > > > kernels, so device type differentiation should already work without > > > > BDF values. > > > > > > > > So does that mean the concern is images are different for devices with > > > > the same vendor:device pairs? There are sites out there dedicated to > > > > dumping AMD's video roms which seem to suggest all discrete devices > > > > would be fine loading the same rom. Is there another platform you are > > > > thinking of where devices with the same vendor:device values would > > > > need different images? > > > > > > That is incorrect. The vbios images are board specific. Using the > > > wrong image can cause a lot of problems. The vbios exists to handle > > > board specific design variations (e.g., the number and type of display > > > connectors, the i2c/aux channel mappings, board specific clock and > > > voltage settings, etc.). The PCI DID just indicates the chip used on > > > the board. The actual board design varies with each AIB vendor (e.g., > > > Sapphire and XFX both make 7900XTX boards, but they can have very > > > different configurations. > > > > Thanks for the explanation, that makes sense. > > > > Is my understanding correct that IGPUs (my case) simply won't have > > vbios available in any other mechanism. If so perhaps this isnt > > feasible in amdgpu as the BDF information is lost in reassignment. > > Depends on the platform, but recent ones use VFCT. That said, there > should only ever be one IGPU in the system so I think we could just > rely on the VID and DID for APUs in this case and check everything for > dGPUs. Is there a reason why you need this option? Even beyond this, I could envision other problems related to APUs and ACPI if these changed. Alex
