[U-Boot] [PATCH v4] nios2: convert dma_alloc_coherent to use malloc_cache_aligned

Marek Vasut
2015-10-12T13:46:13Z

On Monday, October 12, 2015 at 02:55:03 PM, Thomas Chou wrote:
> Hi Marek,

Hi Thomas,

> On 10/12/2015 06:32 PM, Marek Vasut wrote:
> > Wouldn't invalidate_dcache_range() be enough here ? You don't care about
> > the data in the newly allocated area at this point I guess -- either you
> > fill them in and then flush, for DMA from CPU to device OR you receive
> > data from device to CPU and then you invalidate this buffer again.
>
> No. We cannot use invalidate cache here. This is related to cache design
> of nios2, kind of direct mapped cache.

Can you please expand on this ?

btw. I was thinking about this whole cache situation. Please don't get me wrong,
my intention is not to put way more work unto you and/or grind you about minor
details. I hope it doesn't look that way to you.

Best regards,
Marek Vasut