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PCI: Only override AMD USB controller if required

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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@igalia.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Vicki Pfau <vi@endrift.com>
This commit is contained in:
Guilherme G. Piccoli 2023-11-20 13:04:36 -03:00 committed by Bjorn Helgaas
parent d9dcdb4531
commit e585a37e50
1 changed files with 7 additions and 4 deletions
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11
drivers/pci/quirks.c
View File

@ -702,10 +702,13 @@ 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);