On Wed, Mar 06, 2024 at 03:19:52PM +0100, Andreas Larsson wrote:
> > I think that is the correct thing to do then: the only
> > drivers that I see with this dependency are PCI sound cards
> > that apparently rely on DMA to the 16MB ISA range, which is
> > not provided by sparc.
>
> The ZONE_DMA dependency does not seem related to ISA per se. Commit
> 80ab8eae70e5 ("ALSA: Enable CONFIG_ZONE_DMA for smaller PCI DMA masks")
> that started to introduce it did were about ensuring 32-bit masks.
Yikes! That commit is just unbelievable buggy. CONFIG_ZONE_DMA
is only for architetures to select, not drivers. A driver randomly
enabling such an arch zone is just crazy.
I've been wondering for a while if we need some Kconfig magic
so that certain symbols can only be select from arch/* and not
elsewhere to prevent this (we had a few other similar cases like
DMA_MAP_OPS).
