[PATCH 1/3] [MTD] Flex-OneNAND support

[Kyungmin Park]

Hi,

On Thu, Mar 5, 2009 at 1:50 AM, Andrew Morton <akpm at linux-foundation.org> wrote:
> On Wed, 04 Mar 2009 13:41:59 +0200 Adrian Hunter <adrian.hunter at nokia.com> wrote:
>
>> Andrew Morton wrote:
>> >> ...
>> >>
>> >> +static loff_t flexonenand_get_addr(struct onenand_chip *this, int block)
>> >> +{
>> >> +  loff_t ofs = 0;
>> >> +  int die = 0, boundary;
>> >> +
>> >> +  if (ONENAND_IS_DDP(this) && block >= this->density_mask) {
>> >> +          block -= this->density_mask;
>> >> +          die = 1;
>> >> +          ofs = this->diesize[0];
>> >> +  }
>> >> +
>> >> +  boundary = this->boundary[die];
>> >> +  ofs += block << (this->erase_shift - 1);
>> >> +  if (block > (boundary + 1))
>> >> +          ofs += (block - boundary - 1) << (this->erase_shift - 1);
>> >
>> > Both `block' and `boundary' have 32-bit types.  Are you sure that the
>> > left-shift cannot overflow?
>>
>> Only very recently has MTD supported sizes greater than 32 bits internally
>> for any type of flash.  The external APIs (ioctls) are still 32-bit based.
>>
>> For this driver, supporting sizes over 32-bits is a separate issue - and
>> may never be needed.
>
> So it doesn't support files >4G?  What's the max device size (now and
> projected)?

Umm it's not simple question. basically Flex-OneNAND based on NAND
flash technology. It means if NAND flash technology are advanced, it
can also get more size. Currently max Flex-OneNAND has 16 Gib (2GiB)
So it will be exceed the 4GiB soon. but I'm not sure when this device is opened.
I think we know the issues currently and then if the device is opened,
handle this one if required.
How do you think?

Thank you,
Kyungmin Park