]> git.ipfire.org Git - thirdparty/kernel/linux.git/commit
PCI: Add PCI_BRIDGE_NO_ALIAS quirk for ASPEED AST1150
authorNirmoy Das <nirmoyd@nvidia.com>
Wed, 17 Dec 2025 15:45:29 +0000 (07:45 -0800)
committerBjorn Helgaas <bhelgaas@google.com>
Tue, 13 Jan 2026 17:46:33 +0000 (11:46 -0600)
commit550a190494a0d3e933dd6f3b2e9c430f94a30a8c
tree8a224a6fd5981431bb89946f45c4d89c778cb674
parenteeb95c07d5fcaafb1829d5307ce4290cf1dc3190
PCI: Add PCI_BRIDGE_NO_ALIAS quirk for ASPEED AST1150

ASPEED BMC controllers have VGA and USB functions behind a PCIe-to-PCI
bridge that causes them to share the same StreamID:

  [e0]---00.0-[e1-e2]----00.0-[e2]--+-00.0  ASPEED Graphics Family
                                    \-02.0  ASPEED USB Controller

Both devices get StreamID 0x5e200 due to bridge aliasing, causing the USB
controller to be rejected with 'Aliasing StreamID unsupported'.

Per ASPEED, the AST1150 doesn't use a real PCI bus and always forwards
the original Requester ID from downstream devices rather than replacing
it with any alias.

Add a new PCI_DEV_FLAGS_PCI_BRIDGE_NO_ALIAS flag and apply it to the
AST1150.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nirmoy Das <nirmoyd@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://patch.msgid.link/20251217154529.377586-2-nirmoyd@nvidia.com
drivers/pci/quirks.c
drivers/pci/search.c
include/linux/pci.h