Hi Trent,
Trent Piepho wrote:
> On Mon, 2018-12-10 at 14:08 -0800, Thinh Nguyen wrote:
>> Synopsys USB 3.x host HAPS platform has a class code of
>> PCI_CLASS_SERIAL_USB_XHCI, and xhci driver can claim it. However, these
>> devices should use dwc3-haps driver. Change these devices' class code to
>> PCI_CLASS_SERIAL_USB_DEVICE to prevent the xhci-pci driver from claiming
>> them.
>>
>> +
>> + switch (pdev->device) {
>> + case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB3:
>> + case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB3_AXI:
>> + case PCI_DEVICE_ID_SYNOPSYS_HAPSUSB31:
>> + 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);
>> + break;
>> + default:
>> + return;
>> + }
>> +}
>> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
>> + quirk_synopsys_haps);
>> +
> This change breaks my IMX7d based device. This SoC has a PCIe bus
> based on the Synopsys Designware host controller. This has a root
> bridge that shows up as:
>
> 00:00.0 PCI bridge: Synopsys, Inc. Device abcd (rev 01) (prog-if 00 [Normal
> decode])
> 00:00.0 0604: 16c3:abcd (rev 01) (prog-if 00 [Normal decode])
>
>
> Which is to say, class 0x0604, vendor PCI_VENDOR_ID_SYNOPSYS, and the
> device ID 0xabcd.
>
> It looks like there has been a bit of sloppy allocation of PCI device
> codes, as PCI_DEVICE_ID_SYNOPSYS_HAPSUSB3 is also 0xabcd.
>
> So the result of this patch is to try to turn the imx7d PCIe root
> bridge into a USB controller. Which of course breaks it and prevents
> anything behind it, i.e. the endpoint attached to the pci-e bus, from
> working.
>
> Somehow this quirk needs to be more targeted.
Right. Lukas also reported this. It appears that there's a duplicate VID
PID used for the USB controller on HAPS platform. You can review the
discussion subject "Linux Kernel Regression: HAPS quirk breaks PCIe on
i.MX6QP".
I'll send out a patch to resolve this issue. You can check the change to
see if this resolves your issue:
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b0a413f3f7ca..f46e7de9e15d 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -639,8 +639,8 @@ static void quirk_synopsys_haps(struct pci_dev *pdev)
break;
}
}
-DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
- quirk_synopsys_haps);
+DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
+ PCI_CLASS_SERIAL_USB_XHCI, 0, quirk_synopsys_haps);
/*
* Let's make the southbridge information explicit instead of having to
Thanks,
Thinh
