On Tue, Jun 21, 2011 at 01:47:03PM +0200, Marek Szyprowski wrote:

quoted

I also think that it is better to attach and to detach dma_map_ops
dynamically.

What's the point of such operations? Why do you want to change dma
mapping methods in runtime?

That is dangerous. You have to make sure that there are no mappings
granted to the the device driver before changing the dma_ops of a device
at runtime. Otherwise existing mappings for a device may disappear and
confuse the driver and the device.

Joerg