Re: mdio-thunder.c:undefined reference to `mdiobus_unregister'

[Randy Dunlap]

On 06/11/17 19:14, kbuild test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   32c1431eea4881a6b17bd7c639315010aeefa452
> commit: 90eff9096c01ba90cdae504a6b95ee87fe2556a3 net: phy: Allow splitting MDIO bus/device support from PHYs
> date:   3 months ago
> config: x86_64-randconfig-s2-06120830 (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
>         git checkout 90eff9096c01ba90cdae504a6b95ee87fe2556a3
>         # save the attached .config to linux build tree
>         make ARCH=x86_64 
> 
> All errors (new ones prefixed by >>):
> 
>    drivers/built-in.o: In function `thunder_mdiobus_pci_remove':
>>> mdio-thunder.c:(.text+0x2a212f): undefined reference to `mdiobus_unregister'
>>> mdio-thunder.c:(.text+0x2a2138): undefined reference to `mdiobus_free'
>    drivers/built-in.o: In function `thunder_mdiobus_pci_probe':
>    mdio-thunder.c:(.text+0x2a22e7): undefined reference to `devm_mdiobus_alloc_size'
>    mdio-thunder.c:(.text+0x2a236f): undefined reference to `of_mdiobus_register'
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> 

Ugh. I don't know the solution to this one.

CONFIG_MDIO_DEVICE=y
CONFIG_MDIO_THUNDER=y
CONFIG_PHYLIB=m

First 2 lines are OK, but the third line causes the problem...
in drivers/net/phy/Makefile:

# PHYLIB implies MDIO_DEVICE, in that case, we have a bunch of circular
# dependencies that does not make it possible to split mdio-bus objects into a
# dedicated loadable module, so we bundle them all together into libphy.ko
ifdef CONFIG_PHYLIB
libphy-y			+= $(mdio-bus-y)
else
obj-$(CONFIG_MDIO_DEVICE)	+= mdio-bus.o
endif
libphy-$(CONFIG_SWPHY)		+= swphy.o
libphy-$(CONFIG_LED_TRIGGER_PHY)	+= phy_led_triggers.o

obj-$(CONFIG_PHYLIB)		+= libphy.o


So PHYLIB is built as libphy.ko and the mdiobus functions are there
instead of being in mdio-bus.o (so they are not built-in), while the
mdio-thunder driver is built-in.



-- 
~Randy