The quirk is intended to be extremely generic, but we only apply it
to known offending devices.
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---
drivers/pci/quirks.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 923689f..ab620ac 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3385,6 +3385,29 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_JMICRON,
PCI_DEVICE_ID_JMICRON_JMB388_ESD,
quirk_dma_func1_alias);
+/*
+ * A few PCIe-to-PCI bridges fail to expose a PCIe capability, resulting in
+ * using the wrong DMA alias for the device. Some of these devices can be
+ * used as either forward or reverse bridges, so we need to test whether the
+ * device is operating in the correct mode. We could probably apply this
+ * quirk to PCI_ANY_ID, but for now we'll just use known offenders. The test
+ * is for a non-root, non-PCIe bridge where the upstream device is PCIe and
+ * is not a PCIe-to-PCI bridge, then @pdev is actually a PCIe-to-PCI bridge.
+ */
+static void quirk_use_pcie_bridge_dma_alias(struct pci_dev *pdev)
+{
+ if (!pci_is_root_bus(pdev->bus) &&
+ pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
+ !pci_is_pcie(pdev) && pci_is_pcie(pdev->bus->self) &&
+ pci_pcie_type(pdev->bus->self) != PCI_EXP_TYPE_PCI_BRIDGE)
+ pdev->dev_flags |= PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS;
+}
+/* ASM1083/1085, https://bugzilla.kernel.org/show_bug.cgi?id=44881#c46 */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ASMEDIA, 0x1080,
+ quirk_use_pcie_bridge_dma_alias);
+/* Tundra 8113, https://bugzilla.kernel.org/show_bug.cgi?id=44881#c43 */
+DECLARE_PCI_FIXUP_HEADER(0x10e3, 0x8113, quirk_use_pcie_bridge_dma_alias);
+
static struct pci_dev *pci_func_0_dma_source(struct pci_dev *dev)
{
if (!PCI_FUNC(dev->devfn))
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
