On Wednesday 03 February 2016 11:41:40 Murali Karicheri wrote:
> >
> > This looks wrong: I was getting the build warnings originally
> > because of 64-bit dma_addr_t, and that should be the only way that
> > this driver can operate, because in some configurations on keystone
> > there is no memory below 4GB, and there is no dma-ranges property
> > in the DT that shifts around the start of the DMA addresses.
> Arnd,
>
> Why do think so? I see in arch/arm/boot/dts/keystone.dtsi
>
> soc {
> #address-cells = <1>;
> #size-cells = <1>;
> compatible = "ti,keystone","simple-bus";
> interrupt-parent = <&gic>;
> ranges = <0x0 0x0 0x0 0xc0000000>;
> dma-ranges = <0x80000000 0x8 0x00000000 0x80000000>;
>
> AFAIK, On Keystone, dma address is 32 bit and Physical DDR address is
> 64 bit (actually 36 bit, LPAE address). The conversion happens based on
> pfn_offset which is calculated based on the above dma-range property.
My mistake, see my other reply.
Arnd
