On Tue, May 29, 2012 at 5:36 PM, Russell King
[off-list ref] wrote:

The runtime PM support conflicts with the generic AMBA bus PM, and also
causes a potential deadlock with the PL011 driver as it results in
interrupts being enabled beneath a spinlock.

I don't presently see any solution to this other than by removing the
runtime PM support entirely from the DMA engine driver. ?Alternative
suggestions welcome.

I took a look again and cannot see any simple way to do this.

It basically looks like we need to have job submission put stuff
in a queue and kick a worker or kthread to have that do the
get_sync() operation and proceed to submit the descriptors,
lest we always run the risk of being in irq context.

Perfectly doable, but can be done at some other time.

So: Acked-by.

Yours,
Linus Walleij