LS7A EHCI controller doesn't have extended capabilities, so the EECP (EHCI Extended Capabilities Pointer) field of HCCPARAMS register should be 0x0, but it reads as 0xa0 now. This is a hardware flaw and will be fixed in future, now just clear the EECP field to avoid error messages on boot:

...... [ 0.581675] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581699] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581716] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581851] pci 0000:00:04.1: EHCI: unrecognized capability ff ...... [ 0.581916] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.581951] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.582704] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.582799] pci 0000:00:05.1: EHCI: unrecognized capability ff ......

Cc: stable@vger.kernel.org Signed-off-by: Baoqi Zhang zhangbaoqi@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- V2: Add a comment and don't touch pci_ids.h.

drivers/usb/host/pci-quirks.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c index 1f9c1b1435d8..0404489c2f6a 100644 --- a/drivers/usb/host/pci-quirks.c +++ b/drivers/usb/host/pci-quirks.c @@ -958,6 +958,15 @@ static void quirk_usb_disable_ehci(struct pci_dev *pdev) * booting from USB disk or using a usb keyboard */ hcc_params = readl(base + EHCI_HCC_PARAMS); + + /* LS7A EHCI controller doesn't have extended capabilities, the + * EECP (EHCI Extended Capabilities Pointer) field of HCCPARAMS + * register should be 0x0 but it reads as 0xa0. So clear it to + * avoid error messages on boot. + */ + if (pdev->vendor == PCI_VENDOR_ID_LOONGSON && pdev->device == 0x7a14) + hcc_params &= ~(0xffL << 8); + offset = (hcc_params >> 8) & 0xff; while (offset && --count) { pci_read_config_dword(pdev, offset, &cap);