Hi,

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on v4.7-rc2 next-20160609]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Chunfeng-Yun/usb-Add-MediaTek-USB3-DRD-Driver/20160610-153559
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
config: i386-randconfig-x011-06120748 (attached as .config)
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All error/warnings (new ones prefixed by >>):

warning: (USB_MTU3) selects USB_XHCI_MTK which has unmet direct dependencies (USB_SUPPORT && USB && USB_XHCI_HCD && (ARCH_MEDIATEK || COMPILE_TEST))
   drivers/built-in.o: In function `mtu3_probe':

quoted

mtu3_plat.c:(.text+0x21471d): undefined reference to `extcon_get_edev_by_phandle'

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0-DAY kernel test infrastructure                Open Source Technology Center
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