Re: [PATCH] mtd: nand: stm_nand_bch: add new driver

Lee Jones
2014-08-06T10:26:50Z

On Wed, 02 Jul 2014, Brian Norris wrote:
> On Wed, May 28, 2014 at 10:20:05AM +0100, Lee Jones wrote:

[...]

> > + if (((unsigned int)buf & (NANDI_BCH_DMA_ALIGNMENT - 1)) ||
> > + (!virt_addr_valid(buf))) /* vmalloc'd buffer! */
> > + bounce = true;
> > +
> > + p = bounce ? nandi->page_buf : buf;
>
> It looks like you're reimplementing NAND_USE_BOUNCE_BUFFER. Can you try
> using that flag? (You may need to extend it to account for your DMA
> alignment, too.)

NAND_USE_BOUNCE_BUFFER won't work for us unless we can guarantee that
the bounce buffer will always be 64 Byte aligned, which I don't think
we can. Another way to do it would be to assign all of our own
buffers, but I'm really not comfortable fiddling with those as there
are a lot of controller specific intricacies which a) I'm not familiar
with and b) no longer have Angus to fire questions off to and/or
review.

So if you don't mind, I'd really rather use Angus' implementation.
It's only an extra couple of lines and Angus has already tested it to
a high level.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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