[MPlayer-dev-eng] DMA or not DMA

[Ville Syrjälä]

On Wed, Nov 24, 2004 at 10:56:29AM -0500, D Richard Felker III wrote:
> On Wed, Nov 24, 2004 at 12:22:24PM +0200, Ville Syrjälä wrote:
> > On Wed, Nov 24, 2004 at 10:28:24AM +0100, Attila Kinali wrote:
> > > Hi,
> > > 
> > > In a discussion on the open-graphics mailinglist the question DMA 
> > > came up. Basicaly why players like MPlayer don't use DMA but do 
> > > instead a mem2pci/agp copy.
> > > 
> > > >From the discussion, i musst say, that i don't see a real
> > > problem to use DMA and that it would gain some performance.
> > > 
> > > If DMA with MPlayer is just a matter of setting up a DMA-channel,
> > > then i will try to patch mga_vid to use it instead (but that
> > > wont be before the christmas break and after the 2.6 port is finished)
> > > 
> > > Do you see any problems with DMA or would it be just a straight
> > > forward implement and forget thing ?
> > 
> > The problem is multiple drivers trying to use the hardware at the same 
> > time.
> 
> maybe for some people; i don't care about this though. i don't use any
> other drivers that use dma.

The problem isn't with DMA but with the accelerator.

-- 
Ville Syrjälä
syrjala at sci.fi
http://www.sci.fi/~syrjala/