Re: continuous DMA broken (ni_mio_common: buffer overflow) in comedi-cvs

On Sat, Oct 19, 2002 at 08:35:16PM +0200, Tomasz Motylewski wrote:
> 
> Well, I have RT kernel application which uses Comedi just to set up the
> channel list and DMA transfer to a given buffer and then only querries 
> the present position in the buffer. I want the driver to just set up a 
> circular DMA ring and then to leave the hardware alone. It was working
> fine with comedi CVS from about Sat Jul 14 02:33:13 2001
> (ni_pcimio.c/1.37-8, ni_mio_common.c/1.86-7)
> 
> Is it now possible to set up a continuous transfer which just runs by
> itself? 

Continuous DMA works fine.  However, it won't work with your hack.

The best way to do it is to run the command, then access the buffer
pointer using comedi_mmap() and the read buffer offsets using
comedi_get_buf_head_pos() and comedi_set_user_int_count().



dave...

Received on 2002-10-20Z01:17:51