Re: [net:master 1/9] pch_gbe_main.c:(.text+0x510370): undefined reference to `pch_ch_control_write'

[David Miller <davem@davemloft.net>]

From: Haicheng Li <haicheng.li@linux.intel.com>
Date: Sat, 06 Oct 2012 22:07:23 +0800

> On 10/06/2012 09:22 PM, David Miller wrote:
>> From: Haicheng Li<haicheng.li@linux.intel.com>
>> Date: Sat, 06 Oct 2012 20:07:08 +0800
>>
>>> The failure is due to the CONFIG_PPS is not set there, consequently
>>> CONFIG_PTP_1588_CLOCK can not be set as =y anyway.
>>>
>>> So David's patch of "da1586461e53a4dd045738cce309ab488970f0ef [1/9]
>>> pch_gbe: Fix PTP dependencies" is buggy. Furthermore, I think using
>>> "selects" to resolve such dependency issue is not good idea as it
>>> won't visit the dependencies.
>>>
>>> David, I would still suggest to take my original patch:
>>> https://lkml.org/lkml/2012/9/28/70
>>>
>>> + depends on PTP_1588_CLOCK_PCH&&  (PCH_GBE=m || PTP_1588_CLOCK_PCH=y)
>>>
>>> or simply like:
>>
>> This is all very rediculous if you ask me.
>>
>> Why should the user have to know a detail like the underlying
>> PTP chip type just to enable PTP on his networking card?
>>
>> Because that is what you are making him do with your change.
>>
>> Select removed the necessity of the user having to know these
>> things.
> However it possibly breaks the build...
> 
> IMHO, the reason why the dependency of PCH_PTP becomes so tricky is
> that the code of these two modules call the functions of each other
> (bad code structure?). To fix it neatly, either we restructure the
> code or just simply make it:
> + depends on PTP_1588_CLOCK_PCH=y
> 
> For PCH_GBE=m case, it does be able to pass the build test, but I'm
> afraid it won't be smoothly workable via "insmod" due to the
> codependency of these two when PCH_PTP is enabled.

Then why does it work for IXGBE and others who use select?