Hi Oliver,
Have you gotten a chance to test this patch on your test system? I'd
like to get it out, but I want to make sure it fixes your problem.
Thanks,
Sarah Sharp
On Thu, Feb 09, 2012 at 12:13:54PM -0800, Sarah Sharp wrote:
> On some systems with an Intel Panther Point xHCI host controller, the
> BIOS disables the xHCI PCI device during boot, and switches the xHCI
> ports over to EHCI. This allows the BIOS to access USB devices without
> having xHCI support.
>
> The downside is that the xHCI BIOS handoff mechanism will fail because
> memory mapped I/O is not enabled for the disabled PCI device.
> Jesse Barnes says this is expected behavior. The PCI core will enable
> BARs before quirks run, but it will leave it in an undefined state, and
> it may not have memory mapped I/O enabled.
>
> Make the generic USB quirk handler call pci_enable_device() to re-enable
> MMIO, and call pci_disable_device() once the host-specific BIOS handoff
> is finished. This will balance the ref counts in the PCI core. When
> the PCI probe function is called, usb_hcd_pci_probe() will call
> pci_enable_device() again.
>
> This should be backported to kernels as old as 2.6.32. That was the
> first kernel with xHCI support, and no one has complained about BIOS
> handoffs failing due to memory mapped I/O being disabled on other hosts
> (EHCI, UHCI, or OHCI).
>
> Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
> Cc: Oliver Neukum <oneukum@xxxxxxx>
> Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxx
> ---
> drivers/usb/host/pci-quirks.c | 11 +++++++++++
> 1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> index ac53a66..7732d69 100644
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c
> @@ -872,7 +872,17 @@ static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
> */
> if (pdev->vendor == 0x184e) /* vendor Netlogic */
> return;
> + if (pdev->class != PCI_CLASS_SERIAL_USB_UHCI &&
> + pdev->class != PCI_CLASS_SERIAL_USB_OHCI &&
> + pdev->class != PCI_CLASS_SERIAL_USB_EHCI &&
> + pdev->class != PCI_CLASS_SERIAL_USB_XHCI)
> + return;
>
> + if (pci_enable_device(pdev) < 0) {
> + dev_warn(&pdev->dev, "Can't enable PCI device, "
> + "BIOS handoff failed.\n");
> + return;
> + }
> if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> quirk_usb_handoff_uhci(pdev);
> else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
> @@ -881,5 +891,6 @@ static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
> quirk_usb_disable_ehci(pdev);
> else if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI)
> quirk_usb_handoff_xhci(pdev);
> + pci_disable_device(pdev);
> }
> DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);
> --
> 1.7.9
>
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