4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> [ Upstream commit e585a37e5061f6d5060517aed1ca4ccb2e56a34c ] By running a Van Gogh device (Steam Deck), the following message was noticed in the kernel log: pci 0000:04:00.3: PCI class overridden (0x0c03fe -> 0x0c03fe) so dwc3 driver can claim this instead of xhci Effectively this means the quirk executed but changed nothing, since the class of this device was already the proper one (likely adjusted by newer firmware versions). Check and perform the override only if necessary. Link: https://lore.kernel.org/r/20231120160531.361552-1-gpiccoli@xxxxxxxxxx Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Huang Rui <ray.huang@xxxxxxx> Cc: Vicki Pfau <vi@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/pci/quirks.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index a5d49f75e1ac..99a8a24ea79d 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -611,10 +611,13 @@ static void quirk_amd_dwc_class(struct pci_dev *pdev) { u32 class = pdev->class; - /* Use "USB Device (not host controller)" class */ - pdev->class = PCI_CLASS_SERIAL_USB_DEVICE; - pci_info(pdev, "PCI class overridden (%#08x -> %#08x) so dwc3 driver can claim this instead of xhci\n", - class, pdev->class); + if (class != PCI_CLASS_SERIAL_USB_DEVICE) { + /* Use "USB Device (not host controller)" class */ + pdev->class = PCI_CLASS_SERIAL_USB_DEVICE; + pci_info(pdev, + "PCI class overridden (%#08x -> %#08x) so dwc3 driver can claim this instead of xhci\n", + class, pdev->class); + } } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_NL_USB, quirk_amd_dwc_class); -- 2.43.0