Hi Yicong,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on pci/next]
[also build test ERROR on v5.5-rc6 next-20200110]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Yicong-Yang/PCI-Improve-link-speed-presentation-process/20200114-163536
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: ia64-allnoconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 7.5.0
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=7.5.0 make.cross ARCH=ia64 

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

All errors (new ones prefixed by >>):

   drivers/pci/pci-sysfs.o: In function `max_link_speed_show':
>> pci-sysfs.c:(.text+0x1e01): undefined reference to `pci_bus_speed_strings'
   pci-sysfs.c:(.text+0x1e10): undefined reference to `pci_bus_speed_strings'
   drivers/pci/pci-sysfs.o: In function `current_link_speed_show':
   pci-sysfs.c:(.text+0x2070): undefined reference to `pci_bus_speed_strings'
   pci-sysfs.c:(.text+0x2080): undefined reference to `pci_bus_speed_strings'

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