Re: [RFC v2 2/5] dmaengine: Add slave DMA interface

[Dan Williams]

On Jan 30, 2008 5:26 AM, Haavard Skinnemoen <hskinnemoen@xxxxxxxxx> wrote:
[..]
> Right. I'll add a "unsigned int engine_type" field so that engine
> drivers can go ahead and extend the standard dma_device structure.
> Maybe we should add a "void *platform_data" field to the dma_slave
> struct as well so that platforms can pass arbitrary platform-specific
> information to the DMA controller driver?
>

I think we can get away with not adding an engine_type field:
1/ For a given platform there will usually only be one driver active.
For example I have an architecture (IOP) specific dma_copy_to_user
implementation that can safely assume it is talking to the iop-adma
driver since ioat_dma and others are precluded by the Kconfig.
2/ If there was a situation where two dma drivers were active in a
system you could tell them apart by comparing the function pointers,
i.e. dma_device1->device_prep_dma_memcpy !=
dma_device2->device_prep_dma_memcpy.

--
Dan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/