[PATCH 15/15] ARM: mark footbridge as deprecated

[Linus Walleij]

On Wed, Dec 4, 2024 at 3:37 PM Russell King (Oracle)
<linux at armlinux.org.uk> wrote:

> > I am booting it occasionally, last time to test my KCFI patches.
> > But admittedly that is only to test it for other SA110 users. I remember
> > that Christoph had problems consolidating the DMA used in this
> > machine as well so it is standing in the way of useful work.
>
> What problems with DMA? The fact that it uses an offset between
> physical and PCI bus space should be nothing that causes a problem
> for the kernel. As maintainer for Footbridge, I've heard nothing
> about there being any issue.

No issue other than testing and iterating the patches I think.

I was thinking of this patchset to do dma_direct_set_offset():
https://lore.kernel.org/linux-arm-kernel/20200917173229.3311382-3-hch@lst.de/

It seems to have stalled some years ago, but maybe there was
some other reason.

IIRC Christoph was onto me to test it on the NetWinder, but I
couldn't locate a good DMA capable device to test it with.
(Would be the soundblaster but then I needed some userspace...)

Yours,
Linus Walleij