On 9/15/2023 02:08, Lukas Wunner wrote:
On Thu, Sep 14, 2023 at 09:33:54PM -0500, Mario Limonciello wrote:+static bool child_has_amd_usb4(struct pci_dev *pdev) +{ + struct pci_dev *child = NULL; + + while ((child = pci_get_class(PCI_CLASS_SERIAL_USB_USB4, child))) { + if (child->vendor != PCI_VENDOR_ID_AMD) + continue; + if (pcie_find_root_port(child) != pdev) + continue; + return true; + } + + return false; +}What's the purpose of the pcie_find_root_port() check? PCI is a hierarchy, not a graph, so a device cannot have any other Root Port but the one below which you're searching. If the purpose is to check that the port is a Root Port (if the PCI IDs you're using in the DECLARE_PCI_FIXUP_* clauses match non-Root Ports), check for pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT. (No need to check for that in every loop iteration obviously, just check once in the fixup.) Thanks, Lukas
The reason to look for it the way that I did was that there are multiple root ports with the exact same PCI ID.
The problem only occurs on the root port that happens to have an AMD USB4 controller connected.
