[PATCH] ARM:SAMSUNG: Move S3C DMA driver to drivers/dma

Mark Brown broonie at opensource.wolfsonmicro.com
Wed Jun 8 04:55:27 EDT 2011


On Wed, Jun 08, 2011 at 08:21:08AM +0530, Jassi Brar wrote:
> On Wed, Jun 8, 2011 at 3:11 AM, Mark Brown

> > That's fairly unusual, though - usually DMA controllers seem to support
> > chaining requests before they support circular operation, at which point
> > unless the hardware is badly misdone you can just chain another buffer,
> > giving that buffer's worth of time for the CPU to respond.

> While writing PL330 driver, I wasn't able to figure out a way to implement LLI.
> Please have a look at the PL330 trm and suggest if we can implement it in a
> generic way without considering them special requests.
> I know pl080 supports LLI and it's fine.

I'm perfectly prepared to believe that there's poorly designed hardware
out there (either due to just poor design or deploying a controller in
an inappropriate application) that requires us to do things in software;
it's just relatively unusual as users tend to run into issues which
either can't be resolved or are excessively painful to resolve.



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