[PATCH 1/2] ARM: shmobile: sdhi: pass DMA filter from platform code

[Guennadi Liakhovetski]

On Fri, 31 May 2013, Arnd Bergmann wrote:

> On Friday 31 May 2013 16:52:13 Guennadi Liakhovetski wrote:
> > 
> > Thanks for the patches. How about this fix:
> > 
> > http://thread.gmane.org/gmane.linux.kernel.mmc/20619
> > 
> > I think it's a better fix. SHDMA users cannot use other DMA drivers, so, I 
> > don't think we need to pass the filter via the platform data.
> 
> I think it's more a matter of using the API correctly. The dmaengine
> API is an abstraction to separate the slave driver from the master
> through well-defined calls. If you make additional assumptions
> in the slave driver about the master, that is a layering violation.

I think it is a common practice, see e.g.

drivers/mmc/host/omap_hsmmc.c
drivers/mmc/host/davinci_mmc.c

And what do you do for DT-based platforms?

Thanks
Guennadi
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Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/