Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753360AbaJ1NaE (ORCPT ); Tue, 28 Oct 2014 09:30:04 -0400 Received: from mail-qc0-f181.google.com ([209.85.216.181]:59066 "EHLO mail-qc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751792AbaJ1NaA (ORCPT ); Tue, 28 Oct 2014 09:30:00 -0400 MIME-Version: 1.0 In-Reply-To: <1414497280-3126-19-git-send-email-ray.huang@amd.com> References: <1414497280-3126-1-git-send-email-ray.huang@amd.com> <1414497280-3126-19-git-send-email-ray.huang@amd.com> From: Bjorn Helgaas Date: Tue, 28 Oct 2014 07:29:39 -0600 Message-ID: Subject: Re: [PATCH v3 18/19] PCI: Add quirk to prevent AMD NL USB3 DRD to bind with xHCI driver To: Huang Rui Cc: Felipe Balbi , Alan Stern , Greg Kroah-Hartman , Paul Zimmerman , Heikki Krogerus , Jason Chang , Vincent Wan , Tony Li , USB list , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I suggest a subject like this: PCI: Prevent xHCI driver from claiming AMD Nolan USB3 DRD device On Tue, Oct 28, 2014 at 5:54 AM, Huang Rui wrote: > The AMD Nolan (NL) SoC contains a DesignWare USB3 Dual-Role Device that can > be operated either as a USB Host or a USB Device. In the AMD NL platform, > this device ([1022:7912]) has a class code of PCI_CLASS_SERIAL_USB_XHCI > (0x0c0330), which means the xhci driver will claim it. > > But the dwc3 driver is a more specific driver for this device, and we'd > prefer to use it instead of xhci. To prevent xhci from claiming the > device, change the class code to 0x0c03fe, which the PCI r3.0 spec defines > as "USB device (not host controller)". The dwc3 driver can then claim it > based on its Vendor and Device ID. > > Suggested-by: Heikki Krogerus > Cc: Bjorn Helgaas Acked-by: Bjorn Helgaas Please merge along with the rest of your series. > Cc: Jason Chang > Signed-off-by: Huang Rui > --- > drivers/pci/quirks.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 90acb32..1152bef 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -379,6 +379,26 @@ static void quirk_ati_exploding_mce(struct pci_dev *dev) > DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_RS100, quirk_ati_exploding_mce); > > /* > + * In the AMD NL platform, this device ([1022:7912]) has a class code of > + * PCI_CLASS_SERIAL_USB_XHCI (0x0c0330), which means the xhci driver will > + * claim it. > + * But the dwc3 driver is a more specific driver for this device, and we'd > + * prefer to use it instead of xhci. To prevent xhci from claiming the > + * device, change the class code to 0x0c03fe, which the PCI r3.0 spec > + * defines as "USB device (not host controller)". The dwc3 driver can then > + * claim it based on its Vendor and Device ID. > + */ > +static void quirk_amd_nl_class(struct pci_dev *pdev) > +{ > + /* > + * Use 'USB Device' (0x0x03fe) instead of PCI header provided > + */ > + pdev->class = 0x0c03fe; > +} > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_NL_USB, > + quirk_amd_nl_class); > + > +/* > * Let's make the southbridge information explicit instead > * of having to worry about people probing the ACPI areas, > * for example.. (Yes, it happens, and if you read the wrong > -- > 1.9.1 > -- 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/