[Qemu-devel] Re: [PATCH 00/20] VMState: port all i2c devices

[Juha.Riihimaki]

On Sep 11, 2009, at 13:47, ext Juan Quintela wrote:

>>> - i2c->address now are uint8_t, my review of all uses is that they
>>> are always
>>> used as uint8_t (and that is the type that is passed on the
>>> value).  If you know
>>> i2c, please check.  Change 0002 looks big, but it is because as I  
>>> was
>>
>> I would propose that the address has more than 8 bits to be more
>> future-proof. After all, the bus addressing has already been extended
>> to 10 bits: see http://www.i2c-bus.org/addressing/10-bit-addressing/
>
> Then we have a field day, and make incompatible versions from now on.
> VMState use typechecking to make sure that what we save/load has the
> same type that the variable.  And that was not the case for i2c
> addresses.  how many users have old machines saved that they want to  
> restore?

I'm sorry but why is it not possible to start using e.g. 16 bits for  
the address in the save states from now on and still keep the ability  
to read save states generated with previous versions? I'm okay with  
staying on 8 bit addresses only, I would just like to have some solid  
rationale behind that decision.


Juha