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drm/amdgpu: Fix VFCT bus number matching with soft filter

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On systems where PCI bus renumbering occurs (e.g. pci=realloc,
resource conflicts), the runtime bus number may differ from the
BIOS POST bus number recorded in the VFCT table. This causes
amdgpu_acpi_vfct_bios() to fail finding the VBIOS even though
the correct device entry exists.

Introduce amdgpu_acpi_vfct_match() which treats the bus number
as a soft filter: vendor/device/function identity is the hard
requirement, while exact bus match is the preferred path. When
bus numbers disagree but device identity matches, accept the
VFCT entry and log a dev_notice for diagnostics.

Reported-by: Oz Tiram <oz@shift-computing.de>
Closes: https://lore.kernel.org/amd-gfx/20260621173211.28443-1-oz@shift-computing.de/
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260708193518.702584-2-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 11c1416720)
Cc: stable@vger.kernel.org
This commit is contained in:
Mario Limonciello 2026-07-08 14:35:14 -05:00 committed by Alex Deucher
parent a2f895f3c8
commit db7e810880
1 changed files with 40 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
View File

@ -372,6 +372,45 @@ static bool amdgpu_read_disabled_bios(struct amdgpu_device *adev)
}
#ifdef CONFIG_ACPI
/**
* amdgpu_acpi_vfct_match() - Check if a VFCT entry matches the device
* @adev: AMDGPU device
* @vhdr: VFCT image header to check
*
* VFCT entries contain the PCI bus number as recorded during BIOS POST.
* On systems where the kernel renumbers PCI buses (e.g. pci=realloc or
* resource conflicts), the runtime bus number may differ from the POST
* value. Match by device identity (vendor + device + function) and use
* the bus number as a preference: exact bus match is preferred, but when
* the bus numbers disagree we accept the entry if the device identity
* matches.
*
* Returns: 0 on match, -ENODEV on no match
*/
static int amdgpu_acpi_vfct_match(struct amdgpu_device *adev,
VFCT_IMAGE_HEADER *vhdr)
{
/* Vendor and device IDs must always match */
if (vhdr->VendorID != adev->pdev->vendor ||
vhdr->DeviceID != adev->pdev->device)
return -ENODEV;
if (vhdr->PCIDevice != PCI_SLOT(adev->pdev->devfn) ||
vhdr->PCIFunction != PCI_FUNC(adev->pdev->devfn))
return -ENODEV;
/* Exact bus number match - preferred */
if (vhdr->PCIBus == adev->pdev->bus->number)
return 0;
/* Bus mismatch but device identity matches (PCI renumbering case) */
dev_notice(adev->dev,
"VFCT bus number mismatch: table %u != runtime %u, matching by device identity (vendor 0x%04x device 0x%04x)\n",
vhdr->PCIBus, adev->pdev->bus->number,
adev->pdev->vendor, adev->pdev->device);
return 0;
}
static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
{
struct acpi_table_header *hdr;
@ -407,11 +446,7 @@ static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
}
if (vhdr->ImageLength &&
vhdr->PCIBus == adev->pdev->bus->number &&
vhdr->PCIDevice == PCI_SLOT(adev->pdev->devfn) &&
vhdr->PCIFunction == PCI_FUNC(adev->pdev->devfn) &&
vhdr->VendorID == adev->pdev->vendor &&
vhdr->DeviceID == adev->pdev->device) {
!amdgpu_acpi_vfct_match(adev, vhdr)) {
adev->bios = kmemdup(&vbios->VbiosContent,
vhdr->ImageLength,
GFP_KERNEL);