Linux PCI subsystem development
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* [PATCH AUTOSEL 6.7 01/39] PCI: Only override AMD USB controller if required
@ 2024-01-28 16:10 Sasha Levin
  2024-01-28 16:10 ` [PATCH AUTOSEL 6.7 02/39] PCI: switchtec: Fix stdev_release() crash after surprise hot remove Sasha Levin
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Sasha Levin @ 2024-01-28 16:10 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Guilherme G. Piccoli, Bjorn Helgaas, Huang Rui, Vicki Pfau,
	Sasha Levin, linux-pci

From: "Guilherme G. Piccoli" <gpiccoli@igalia.com>

[ 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@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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 d55a3ffae4b8..057cd5bb89f9 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -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);
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-01-28 16:12 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-01-28 16:10 [PATCH AUTOSEL 6.7 01/39] PCI: Only override AMD USB controller if required Sasha Levin
2024-01-28 16:10 ` [PATCH AUTOSEL 6.7 02/39] PCI: switchtec: Fix stdev_release() crash after surprise hot remove Sasha Levin
2024-01-28 16:10 ` [PATCH AUTOSEL 6.7 16/39] PCI: Fix 64GT/s effective data rate calculation Sasha Levin
2024-01-28 16:10 ` [PATCH AUTOSEL 6.7 17/39] PCI/AER: Decode Requester ID when no error info found Sasha Levin

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