Re: [PATCH 5/4] ARM: footbridge: remove custom DMA address handling

Russell King (Oracle)
2022-08-25T10:36:05Z

On Thu, Aug 25, 2022 at 11:17:52AM +0200, Arnd Bergmann wrote:
> -/*
> - * The footbridge is programmed to expose the system RAM at 0xe0000000.
> - * The requirement is that the RAM isn't placed at bus address 0, which
> - * would clash with VGA cards.
> - */
> -#define BUS_OFFSET 0xe0000000
> -#define __virt_to_bus(x) ((x) + (BUS_OFFSET - PAGE_OFFSET))
> -#define __bus_to_virt(x) ((x) - (BUS_OFFSET - PAGE_OFFSET))

... and this tells you why that is with ISA devices.

So, one hell of a big NAK to this patch, sorry.

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