RE: [PATCH 1/3] DMAENGINE: generic slave channel control

[Koul, Vinod]

> ? Are you using memcpy() to talk to slaves?
Yes, I don't have sg support yet, that's something I need to add next.

> I was assuming all slave communication was to use sglists through
> the .device_prep_slave_sg() call. This is currently the design constraint,
> memcpy() will by design increase both source and destination address
> and also always operate on the memory bus.
> 
> (If you need reconfiguration also for memcpy() I think will be a
> different issue, I'm only looking at slaves now.)
> 
> With only the slave interface the dma_chan struct can be deferred
> by the DMA engine into a local struct which has this address configured
> from the platform, statically.
> 
> The runtime configuration API is exactly about being able to reconfigure
> even the source/destination address at runtime. This is why
> these are on the interface.
Okay looking at the sg API, now I can understand why you need the address in
this structure, I would also need that in future.
One suggestion since we are giving io address here, how about naming the 
variable as io_addr, and we can add comment to be used for sg operations as io 
addr if anyone wants to use memcpy() they can ignore this


Thanks
Vinod
--
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/