torvalds/linux
3
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-03-22 07:27:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

PCI: Add PCI_BRIDGE_NO_ALIAS quirk for ASPEED AST1150

Browse Source 
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
This commit is contained in:
Nirmoy Das
2025-12-17 07:45:29 -08:00
committed by Bjorn Helgaas
parent eeb95c07d5
commit 550a190494
3 changed files with 17 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/pci/quirks.c
View File

@@ -4453,6 +4453,16 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_BROADCOM, 0x9000,
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_BROADCOM, 0x9084,
quirk_bridge_cavm_thrx2_pcie_root);
/*
* AST1150 doesn't use a real PCI bus and always forwards the requester ID
* from downstream devices.
*/
static void quirk_aspeed_pci_bridge_no_alias(struct pci_dev *pdev)
{
pdev->dev_flags |= PCI_DEV_FLAGS_PCI_BRIDGE_NO_ALIAS;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ASPEED, 0x1150, quirk_aspeed_pci_bridge_no_alias);
/*
* Intersil/Techwell TW686[4589]-based video capture cards have an empty (zero)
* class code. Fix it.

2
drivers/pci/search.c
View File

@@ -86,6 +86,8 @@ int pci_for_each_dma_alias(struct pci_dev *pdev,
case PCI_EXP_TYPE_DOWNSTREAM:
continue;
case PCI_EXP_TYPE_PCI_BRIDGE:
if (tmp->dev_flags & PCI_DEV_FLAGS_PCI_BRIDGE_NO_ALIAS)
continue;
ret = fn(tmp,
PCI_DEVID(tmp->subordinate->number,
PCI_DEVFN(0, 0)), data);

5
include/linux/pci.h
View File

@@ -248,6 +248,11 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_HAS_MSI_MASKING = (__force pci_dev_flags_t) (1 << 12),
/* Device requires write to PCI_MSIX_ENTRY_DATA before any MSIX reads */
PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST = (__force pci_dev_flags_t) (1 << 13),
/*
* PCIe to PCI bridge does not create RID aliases because the bridge is
* integrated with the downstream devices and doesn't use real PCI.
*/
PCI_DEV_FLAGS_PCI_BRIDGE_NO_ALIAS = (__force pci_dev_flags_t) (1 << 14),
};
enum pci_irq_reroute_variant {