Hi Arnd,

I love your patch! Yet something to improve:

[auto build test ERROR on tnguy-next-queue/dev-queue]
[also build test ERROR on v5.14-rc3 next-20210723]
[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/Arnd-Bergmann/ethernet-intel-fix-PTP_1588_CLOCK-dependencies/20210726-164755
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue.git dev-queue
config: mips-randconfig-r002-20210726 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project c63dbd850182797bc4b76124d08e1c320ab2365d)
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
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/400b6b5bda753bdd933ea7f6b55be00cc4a692ed
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Arnd-Bergmann/ethernet-intel-fix-PTP_1588_CLOCK-dependencies/20210726-164755
        git checkout 400b6b5bda753bdd933ea7f6b55be00cc4a692ed
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

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 >>):

>> drivers/i2c/Kconfig:8:error: recursive dependency detected!
   drivers/i2c/Kconfig:8: symbol I2C is selected by IGB
   drivers/net/ethernet/intel/Kconfig:87: symbol IGB depends on PTP_1588_CLOCK
   drivers/ptp/Kconfig:8: symbol PTP_1588_CLOCK is implied by MLX4_EN
   drivers/net/ethernet/mellanox/mlx4/Kconfig:6: symbol MLX4_EN depends on NET_VENDOR_MELLANOX
   drivers/net/ethernet/mellanox/Kconfig:6: symbol NET_VENDOR_MELLANOX depends on I2C
   For a resolution refer to Documentation/kbuild/kconfig-language.rst
   subsection "Kconfig recursive dependency limitations"


vim +8 drivers/i2c/Kconfig

da3c6647ee0871 Lan Tianyu         2014-05-20   7  
da3c6647ee0871 Lan Tianyu         2014-05-20  @8  config I2C
^1da177e4c3f41 Linus Torvalds     2005-04-16   9  	tristate "I2C support"
194684e596af4b Mika Kuoppala      2009-12-06  10  	select RT_MUTEXES
4d5538f5882a6b Benjamin Tissoires 2016-10-13  11  	select IRQ_DOMAIN
a7f7f6248d9740 Masahiro Yamada    2020-06-14  12  	help
622e040d577dc8 Michael Witten     2011-07-08  13  	  I2C (pronounce: I-squared-C) is a slow serial bus protocol used in
^1da177e4c3f41 Linus Torvalds     2005-04-16  14  	  many micro controller applications and developed by Philips.  SMBus,
^1da177e4c3f41 Linus Torvalds     2005-04-16  15  	  or System Management Bus is a subset of the I2C protocol.  More
^1da177e4c3f41 Linus Torvalds     2005-04-16  16  	  information is contained in the directory <file:Documentation/i2c/>,
^1da177e4c3f41 Linus Torvalds     2005-04-16  17  	  especially in the file called "summary" there.
^1da177e4c3f41 Linus Torvalds     2005-04-16  18  
^1da177e4c3f41 Linus Torvalds     2005-04-16  19  	  Both I2C and SMBus are supported here. You will need this for
^1da177e4c3f41 Linus Torvalds     2005-04-16  20  	  hardware sensors support, and also for Video For Linux support.
^1da177e4c3f41 Linus Torvalds     2005-04-16  21  
^1da177e4c3f41 Linus Torvalds     2005-04-16  22  	  If you want I2C support, you should say Y here and also to the
^1da177e4c3f41 Linus Torvalds     2005-04-16  23  	  specific driver for your bus adapter(s) below.
^1da177e4c3f41 Linus Torvalds     2005-04-16  24  
^1da177e4c3f41 Linus Torvalds     2005-04-16  25  	  This I2C support can also be built as a module.  If so, the module
^1da177e4c3f41 Linus Torvalds     2005-04-16  26  	  will be called i2c-core.
^1da177e4c3f41 Linus Torvalds     2005-04-16  27  

---
0-DAY CI Kernel Test Service, Intel Corporation
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