On Fri, 31 May 2013, Arnd Bergmann wrote:

On Friday 31 May 2013 16:52:13 Guennadi Liakhovetski wrote:

quoted

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