Re: [PATCH v3 2/4] of: move of_dma_configure() to device, c to help re-use

Arnd Bergmann
2015-01-08T08:40:10Z

On Wednesday 07 January 2015 17:37:56 Rob Herring wrote:
> On Wed, Jan 7, 2015 at 12:49 PM, Murali Karicheri <m-karicheri2-l0cyMroinI0@public.gmane.org> wrote:
>
> > + ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
> > + if (ret < 0) {
> > + dma_addr = offset = 0;
> > + size = dev->coherent_dma_mask + 1;
>
> If coherent_dma_mask is DMA_BIT_MASK(64), then you will overflow and
> have a size of 0. There may also be a problem when the mask is only
> 32-bit type.

The mask is always a 64-bit type, it's not optional. But you are right,
the 64-bit mask case is broken, so I guess we have to fix it differently
by always passing the smaller value into arch_setup_dma_ops and
adapting that function instead.

Arnd