Arnd Bergmann <arnd@arndb.de> writes:

> On Wednesday, June 1, 2016 11:43:30 PM CEST Gerd Hoffmann wrote:
>> +	/* Parse OF address directly to get the physical address for
>> +	 * DMA to our registers.
>> +	 */
>> +	host->phys_addr = be32_to_cpup(of_get_address(pdev->dev.of_node, 0,
>> +						      NULL, NULL));
>
> This looks broken on 64-bit systems when #address-cells=<2>, or if there
> is an intermediate bus with a non-empty ranges property.
>
> What's wrong with platform_get_resource(pdev, IORESOURCE_MEM, 0)?

I'll get to the rest of the review later, but this is a weird pattern
that we have in several bcm2835-related drivers.

We need the address as seen by the DMA controller, not the address from
the ARM's perspective (which is offset by the dma-ranges DT property).
This is the way that people have figured out to get that address.