Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965601Ab2B1BUv (ORCPT ); Mon, 27 Feb 2012 20:20:51 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:58867 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965581Ab2B1BTs (ORCPT ); Mon, 27 Feb 2012 20:19:48 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of gregkh@linuxfoundation.org designates 10.68.242.201 as permitted sender) smtp.mail=gregkh@linuxfoundation.org MIME-Version: 1.0 Message-Id: <20120228010432.852116968@linuxfoundation.org> User-Agent: quilt/0.51-17.1 Date: Mon, 27 Feb 2012 17:05:08 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Sarah Sharp , Oliver Neukum , Jesse Barnes Subject: [ 39/72] USB: Fix handoff when BIOS disables host PCI device. In-Reply-To: <20120228010511.GA8453@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2811 Lines: 73 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarah Sharp commit cab928ee1f221c9cc48d6615070fefe2e444384a upstream. 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 back ported to kernels as old as 2.6.31. 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 Acked-by: Oliver Neukum Cc: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/pci-quirks.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/usb/host/pci-quirks.c +++ b/drivers/usb/host/pci-quirks.c @@ -872,7 +872,17 @@ static void __devinit quirk_usb_early_ha */ 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_ha 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/