Hi Shengjiu,

I love your patch! Yet something to improve:

[auto build test ERROR on asoc/for-next]
[also build test ERROR on shawnguo/for-next v5.12-rc2]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Shengjiu-Wang/Add-audio-driver-base-on-rpmsg-on-i-MX-platform/20210308-213802
base:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/0cabc4a6bce0db6d63de8cfffbdc5fe53c4ea6f5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Shengjiu-Wang/Add-audio-driver-base-on-rpmsg-on-i-MX-platform/20210308-213802
        git checkout 0cabc4a6bce0db6d63de8cfffbdc5fe53c4ea6f5
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=sh 

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

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__clk_get_name" [sound/soc/fsl/snd-soc-fsl-rpmsg.ko] undefined!
ERROR: modpost: "__delay" [drivers/net/mdio/mdio-cavium.ko] undefined!
ERROR: modpost: "__udivdi3" [fs/btrfs/btrfs.ko] undefined!
ERROR: modpost: "__umoddi3" [fs/btrfs/btrfs.ko] undefined!

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
   Depends on SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && HAS_DMA
   Selected by
   - SND_ATMEL_SOC_SSC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC
   - SND_ATMEL_SOC_SSC_PDC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && ATMEL_SSC

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org