[PATCH 2/4] dmaengine: dw_dmac: move to generic DMA binding

Russell King - ARM Linux linux at arm.linux.org.uk
Sat Feb 16 21:51:59 EST 2013


On Sat, Feb 16, 2013 at 10:07:39AM +0000, Arnd Bergmann wrote:
> On Saturday 16 February 2013, Viresh Kumar wrote:
> > On 15 February 2013 23:51, Arnd Bergmann <arnd at arndb.de> wrote:
> > > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
> > >  {
> > 
> > > +       dws->cfg_hi     = 0xffffffff;
> > > +       dws->cfg_lo     = 0xffffffff;
> > 
> > s/0xffffffff/-1 ?
> 
> It's an 'unsigned int'. While -1 would work here, I always find it a little
> odd to rely on that feature of the C language.

However, relying on an 'int' being 32-bits is also rather odd, and
probably much more dubious too.  If you want to set all bits in an
int, the portable way to do that is ~0.


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