[PATCH 2/2] ixp4xx_eth: Setup coherent_dma_mask

[Simon Kågström]

On Wed, 5 Mar 2014 10:55:02 +0100
Krzysztof Hałasa <khalasa at piap.pl> wrote:

> Russell King - ARM Linux <linux at arm.linux.org.uk> writes:

> > If you have drivers missing this call, that's part of the problem:
> >
> > | For correct operation, you must interrogate the kernel in your device
> > | probe routine to see if the DMA controller on the machine can properly
> > | support the DMA addressing limitation your device has.
> 
> Well, we already know it can. Actually, the DMA controller is a part of
> the CPU + RAM controller chip :-)
> 
> But I guess with this new wording it's something the drivers can use.

With that wording, I would say these two patches should be applicable:
The first corrects dma_set_coherent_mask() to actually setup the
coherent_dma_mask (and make it applicable outside of the PCI domain)
and the second sets it up in the driver, as per

> > | support the DMA addressing limitation your device has.  It is good
> > | style to do this even if your device holds the default setting,
> > | because this shows that you did think about these issues wrt. your
> > | device.

Without these patches (or Krzysztofs patch), the ixp4xx platform is
broken for many common configurations.

// Simon