Subject: Re: TC bba audio problem on DEC3000/300
To: Jason R Thorpe <thorpej@zembu.com>
From: Gregory McGarry <g.mcgarry@ieee.org>
List: port-alpha
Date: 07/18/2000 07:54:50
Jason R Thorpe wrote:
> > The following patch seems to fix this and now my 3000/300 can
> > speak some Japanese :-) But I'm not sure how it works on pmax...
>
> It looks like this patch will be okay on the DECstation, as well. The
> new arch/pmax/tc/asc_ioasic.c clears the pointer reload interrupt bit
> for the SCSI as well...
I think this is a special case for doing polled I/O:
/*
* When doing polled I/O, the SCSI bits in the interrupt register won't
* get cleared by the interrupt processing. This will cause the DMA
* address registers to not load on the next DMA transfer.
* Check for these bits here, and clear them if needed.
*/
As the comment alludes, generally the correct place is to do it in the
machine-dependent 'interrupt processing'.
-- Gregory McGarry <g.mcgarry@ieee.org>