amdgpu_acpi_vfct_match(9)

💖 amdgpu_acpi_vfct_match 💖

okay so bestie, welcome to amdgpu_acpi_vfct_match(9) from the Kernel API Manual — yes, that's the whole title, we're not skipping the intro, it's giving "full government name" energy ✨

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🌸 NAME 🌸

amdgpu_acpi_vfct_match — check if a VFCT entry matches the device 🎀

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🦋 SYNOPSIS 🦋

int amdgpu_acpi_vfct_match (struct amdgpu_device *adev ,
VFCT_IMAGE_HEADER *vhdr );

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💅 ARGUMENTS 💅

• adev — the AMDGPU device, our main character 🫶
• vhdr — the VFCT image header we're checking, like the vibe check but for headers 💀

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✨ DESCRIPTION ✨

ok so here's the tea ☕ — VFCT entries contain the PCI bus number as recorded during BIOS POST. literally baked in at POST time, no cap.

but here's the plot twist 😭 on systems where the kernel renumbers PCI buses — think pci=realloc or resource conflicts — the runtime bus number may differ from the POST value. so the number you thought you knew? not the same number anymore. iconic of the kernel honestly 🙈

so instead of just trusting the bus number, this function matches by device identity (vendor + device + function) and uses the bus number as a preference:

• exact bus match? preferred, slay 💖
• bus numbers disagree? still accept the entry if the device identity matches 👑

like, identity stays the same even when the bus number switches up its whole look. periodt.

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🔥 RETURN 🔥

• 0 — on match 🎉
• -ENODEV — on no match 💀

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
• amdgpu_atrm_call(9)

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ok that's the whole page, go be amazing with your VFCT matching bestie 👑💜

and for the cute lil sign-off: this whole thing lives in ./drivers/gpu/drm/amd/amdgpu, dated October 2026 — mark your calendars, the future is now 🧚✨🌸