Hi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[cannot apply to v5.3-rc4 next-20190814]
[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/jun-li-nxp-com/usb-chipidea-add-role-switch-class-support/20190815-040028
config: arm-multi_v5_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/usb/chipidea/core.o: In function `ci_hdrc_remove':
   core.c:(.text+0xec4): undefined reference to `usb_role_switch_unregister'
   drivers/usb/chipidea/core.o: In function `ci_hdrc_probe':
   core.c:(.text+0x1328): undefined reference to `usb_role_switch_unregister'
>> core.c:(.text+0x14c8): undefined reference to `usb_role_switch_register'

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0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation