[PATCH 01/18] mtd: abstract last MTD partition parser argument

[Dmitry Eremin-Solenikov]

On 6/22/11, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
> On Wed, 2011-06-22 at 12:21 +0400, Dmitry Eremin-Solenikov wrote:
>> On 6/22/11, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
>> > I see a lot of checkpatch.pl warnings, could you please take a look?
>> >
>> > Also, my gcc produces warnings with this patch because you have not
>> > fixed up MPT parsers, e.g., like this:
>>
>> Sorry, I was also busy that time and forgot about this :)
>>
>> BTW: the patches should be applicable clearly to the l2-mtd at the time
>> I've sent them.
>>
>> I'll fix all of your comments except this one:
>>
>> > Could you please embrace the origin field into an anonymous union - once
>> > we add the of_node field they do not have to be at separate addresses. I
>> > mean:
>> >
>> > struct mtd_part_parser_data {
>> > 	union {
>> > 		unsigned long origin;
>> > 		struct device_node *of_node;
>> > 	};
>> > };
>>
>> No, no and no. This data is passed to all parsers, so it should be valid
>> for all
>> of them. Either we have to add a way to specify, what exactly we have
>> provided,
>> or we have to leave data as separate struct fields.
>
> I do not see why we should waste memory - union will work well. This is
> parser-specific object and the parser should know which fields belong to
> him. And this object is not shared between parsers so they cannot screw
> each other. Yes, this is not the most beautiful way to go, but it is
> simple enough and suits this situation, I think.

It _is_ shared between parsers. See: driver creates one mtd_part_parser_data
instance, populates it and passes to parse_mtd_partitions (directly or
indirectly).
Then each parser uses the same object to get data. Consider what will happen
when ixp4xx driver (which currently uses origin for RedBoot) will also gain
OF support (as it's expected for all ARM-related things). It will set both
origin (for RedBoot) and of_node (for ofpart).

-- 
With best wishes
Dmitry