[alsa-devel] [PATCH] ALSA sound driver for SEGA Dreamcast AICA (pcm)

Adrian McMenamin adrianmcmenamin at gmail.com
Tue May 15 23:31:15 CEST 2007


On 15/05/07, Adrian McMenamin <adrianmcmenamin at gmail.com> wrote:
> On 15/05/07, Heikki Orsila <shdl at zakalwe.fi> wrote:
> > I still noticed some type cleanups, and possibly a good debug message..
> >
> > On Mon, May 14, 2007 at 11:14:55PM +0100, Adrian McMenamin wrote:
> > > +/* spu_memload - write to SPU address space */
> > > +static void spu_memload(u32 toi, void __iomem * from, int length)
> > > +{
> > > +     u32 __iomem *froml = from;
> > > +     u32 __iomem *to = (u32 __iomem *) (SPU_MEMORY_BASE + toi);
> > > +     int i, val;
> >
> > You should use "void *from" because it's not IO memory. Also, use "u32 val"
> > since that is the native type of "u32 *from".
> >
> > > +     length = DIV_ROUND_UP(length, 4);
> > > +     spu_write_wait();
> > > +     for (i = 0; i < length; i++) {
> > > +             val = *froml;
> > > +             writel(val, to);
> > > +             froml++;
> > > +             to++;
> > > +             if (i && !(i % 8))
> > > +                     spu_write_wait();
> > > +     }
> > > +}
> >
> > It seems a small simplification is possible:
> >
> >         /* remove first spu_write_wait(); */
> >         for (i = 0; i < length; i++) {
> >                 if (!(i % 8))
> >                         spu_write_wait();
> >                 val = *froml;
> >                 ...
> >         }
> >
>
> No, that would be dangerous because we don't know what state the FIFO
> is in when this is called.
>


Sorry, should think before I post!


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