Re: [PATCH v4 2/3] omap4: opp: add OPP table data

[Nishanth Menon <nm@ti.com>]

Kevin Hilman had written, on 11/22/2010 06:09 PM, the following:
> Nishanth Menon <nm@ti.com> writes:
> 
>> Kevin Hilman wrote, on 11/22/2010 05:19 PM:
>>> Nishanth Menon<nm@ti.com>  writes:
>>>
>>>> This patch adds OPP tables for OMAP4. New file has been added to keep
>>>> the OMAP4 opp tables and the registration of these tables with the
>>>> generic opp framework by OMAP SoC OPP interface.
>>> [...]
>>>
>>>> diff --git a/arch/arm/mach-omap2/opp.c b/arch/arm/mach-omap2/opp.c
>>>> index 66e12be..48a553f 100644
>>>> --- a/arch/arm/mach-omap2/opp.c
>>>> +++ b/arch/arm/mach-omap2/opp.c
>>>> @@ -131,4 +131,5 @@ static int __init omap_init_opp_table(struct omap_opp_def *opp_def,
>>>>
>>>>   /* omap3 opps */
>>>>   #include "opp3xxx_data.c"
>>>> -
>>>> +/* omap4 opps */
>>>> +#include "opp4xxx_data.c"
>>> I'm not sure I like the including of C files.  Any reason you prefer
>>> this to just adding them to the Makefile?  e.g. opp24xx_dta.c are
>>> compiled in via Makefile and these two are included.
>> I dont buy it. I am seeing us go around in circles for this:
>> http://marc.info/?l=linux-omap&m=128986880406272&w=2
>> a) we dont want others to use specifics implemented in opp.c in other
>> files (e.g. board files)
> 
> not sure how this is prevented.
The approach is as follows:
the #defines and struct definitions are in opp.c
opp{3,4}xxx_data.c use the same - by itself wont build because they need 
the defines in opp.c
that way, there is no possibility of clean hacks possible except to 
follow the current mechanism for a future omap silicon

The main objective was to restrict the potential of board developers 
from hacking the default OPP table - which would be possible by exposing 
the headers for board files - which as Thomas rightly pointed out in the 
  thread I pointed out,  opens up a possibility for board files to 
include them as well and re-instantiate the table again..

> 
>> b) we have many similar usage in linux kernel - so this usage is not
>> first time.
>> c) opp2xx usage is very different from opp3/4 usage
> 
> I'm not going to insist on one way or the other, just stating my
> preference for not including C files from C files without good
> justification.  You've stated your reasons, I guess Tony can decide.
okay by me - will post a v5 after seeing the final decision on that front :)

-- 
Regards,
Nishanth Menon