CONFIG_ISA_DMA_API without CONFIG_GENERIC_ISA_DMA

[Timur Tabi]

On Thu, Feb 25, 2010 at 3:40 PM, Scott Wood <scottwood at freescale.com> wrote:
> Commit fb4f0e8832e0075849b41b65f6bb9fdfa7593b99 (Enable GENERIC_ISA_DMA if
> FSL_ULI1575 to fix compile issue) tries to deal with this, but it ties it to
> CONFIG_FSL_ULI1575, which is not selected in a p4080ds-only config.
>
> It seems that ULI isn't really relevant to the actual problem, which is that
> we enable ISA DMA API support without selecting an implementation.  Whether
> a certain chip is on the board that has an actual ISA interface is
> irrelevant to the build breakage.
>
> Where did the dependency list for GENERIC_ISA_DMA come from?  Are there any
> legitimate cases on powerpc where we want to select ISA_DMA_API but not
> GENERIC_ISA_DMA (i.e. we have an alternate implementation)?

I've been bitten by this issue as well on the P1022DS.  If I enable
ALSA, then some ISA support also gets compile (by itself, that's
probably a bug), and that code calls claim_dma_lock().

This problem's been around for a long time.  I would have encountered
it on the MPC8610 HPCD, but that board has an ULI 1575.  The P1022Ds
doesn't.

-- 
Timur Tabi
Linux kernel developer at Freescale