RFC: [PATCH] MTD OneNAND: multiblock erase support

[Mika Korhonen]

2009/6/15 Adrian Hunter <adrian.hunter at nokia.com>:
> Mika Korhonen wrote:
>>
>> I wrote an initial support for OneNAND multiblock erase feature.  When
>> done in maximum 64 eraseblock batches multiblock erase is up to 30x
>> faster than block-by-block erase (not including erase verify, though).
>>
>> However, I only had possibility to test this with an OMAP board, so I
>> don't know if e.g. the default onenand_wait needs adjustment. Also for
>> Flex-OneNAND the support goes off. Does Flex even have mb erase?
>>
>> What do you think?
>
> I expect all OneNAND support multiblock erase, so the config should
> go away.  Kyungmin can probably comment on that.

Yes, I was thinking about that as well. Is it included in all chips?

> Waiting for multiblock-erase, you should probably spin, not use the
> interrupt line.  You should change the wait function in
> onenand_base and omap2.c.
>
> You should handle multiple multiblock erases.
>
> You should check for bad blocks *before* doing command 0x95

Ok

> Waiting for erase-verify, you should probably spin too.
>
I just tried that and it looks like spinning in verify read makes a
difference as I got 30% faster total time for 1600 block erase.

Thanks for good advice!
Mika