[RFC 23/34] dmaengine: PL08x: re-jig the starting of txds

[Russell King - ARM Linux]

On Thu, May 31, 2012 at 09:14:15AM +0800, Linus Walleij wrote:
> On Tue, May 29, 2012 at 5:43 PM, Russell King
> <rmk+kernel at arm.linux.org.uk> wrote:
> 
> > Rather than code the de-queue of the txd several times, move that into
> > the start_txd function.  Rename this to better illustrate what it's
> > now doing, and call this function when starting a delayed memcpy().
> >
> > Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> 
> > +                               /*
> > +                                * Eww.  We know this isn't going to deadlock
> > +                                * but lockdep probably doens't.
> 
> Speling...
> 
> > +                                */
> > +                               spin_lock(&waiting->lock);
> > +                               pl08x_start_next_txd(waiting);
> > +                               spin_unlock(&waiting->lock);
> 
> I've seen this construct in the past and have no better suggestions...

I have no way to test whether my statement is true as I can't get enough
DMA engine usage through the PL011 transmit support to check what happens.
So the statement is purely theoretical.

> Acked-by: Linus Walleij <linus.walleij at linaro.org>
> 
> Yours,
> Linus Walleij
>