[PATCH 07/11] fsmc/nand: Provide contiguous buffers to dma

Linus Walleij linus.walleij at linaro.org
Tue Oct 16 06:05:12 EDT 2012

On Tue, Oct 16, 2012 at 9:14 AM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
> On Mon, 2012-10-15 at 21:51 +0200, Linus Walleij wrote:
>> On Mon, Oct 15, 2012 at 6:27 PM, Brian Norris
>> <computersforpeace at gmail.com> wrote:
>> > I would prefer not building a solution that hopes kmalloc() can get a
>> > large contiguous buffer (remember, eraseblock sizes come as large as
>> > 2MB these days). A real solution like CMA or scatter-gather seems like
>> > a better idea.
>> +1 on that, and as I think I illustrated the MMC subsystem is using
>> the block layer helpers to form scatter-gather lists for it's requests.
>> I don't see why the MTD subsystem need to be very different?
> This is good idea, the problem is that it is a bit more work than
> hacking the driver, so most people prefer the latter. By removing all
> kmalloc()'s I basically wish to force people to go this way.
> What are the SC functions names you refer?

I'm mainly thinking of blk_rq_map_sg()
from block/blk-merge.c

Linus Walleij

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