On Fri, Sep 21, 2018 at 11:56:16PM +0530, Himanshu Jha wrote: > Hi Song, > > On Fri, Sep 21, 2018 at 04:10:16PM +0800, kbuild test robot wrote: > > Hi Song, > > > > Thank you for the patch! Yet something to improve: > > > > [auto build test ERROR on iio/togreg] > > [also build test ERROR on v4.19-rc4 next-20180920] > > [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/Song-Qiang/iio-magnetometer-hmc5843-Clean-up-redundant-code/20180921-091239 > > base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg > > config: x86_64-randconfig-u0-09211331 (attached as .config) > > compiler: gcc-5 (Debian 5.5.0-3) 5.4.1 20171010 > > reproduce: > > # save the attached .config to linux build tree > > make ARCH=x86_64 > > > > All errors (new ones prefixed by >>): > > > > >> ERROR: "hmc5843_volatile_table" [drivers/iio/magnetometer/hmc5843_i2c.ko] undefined! > > >> ERROR: "hmc5843_readable_table" [drivers/iio/magnetometer/hmc5843_i2c.ko] undefined! > > >> ERROR: "hmc5843_writable_table" [drivers/iio/magnetometer/hmc5843_i2c.ko] undefined! > > You would need to export these above symbols using EXPORT_SYMBOL() > to be used by i2c/spi modules. > > But on the other hand, exporting too many symbols is a bad idea since > it is only used for this driver and not at any other place in IIO. > So, in my opinion drop this patch and leave the code as-is. > > https://lkml.org/lkml/2018/7/16/566 --> worth reading > > > Thanks > -- > Himanshu Jha > Undergraduate Student > Department of Electronics & Communication > Guru Tegh Bahadur Institute of Technology Hi Himanshu, You're right, that's exactly what I was missing! I saw the link you mentioned above and I also think that's a very good idea to limit the scope of symbols. But I don't know when this work can be applied to the kernel, as it seems like a not little change for the build infrastructure. I think this maybe a common problem for some drivers. Divers for bmc150 in drivers/iio/accel/bmc-150-accel-core.c did the same exporting stuff as I was prefered. So I think even if either exporting or duplicating is not good enough, one must be choosed for now. I think this is a topic that I have some ideas but not experienced enough to say what should we do is better. I would like to hear Jonathan's ideas about this. If this patched shouldn't be applied, then maybe bmc150 should be patched. yours, Song Qiang
