Re: [PARPORT] ECP printing problem

From: Tim Waugh (
Date: Wed Oct 02 2002 - 06:11:29 EDT

  • Next message: Matthew Green: "[PARPORT] pcd fails to cooperate"

    On Tue, Oct 01, 2002 at 02:12:19PM -0400, Blaise Gassend wrote:

    > > > I have a DMA read routine working for my cpia camera, but am having
    > > > trouble adapting it to the general parport driver. I sent a message
    > > > about my problems a few months ago, but got no replies. If any parport
    > > > gurus were willing to give me a hand it should be possible to get the
    > > > routine working with very little work.
    > >
    > > The trouble is that the DMA support in the parport driver is known to
    > > be unreliable. We never traced it down; it could be due to hardware
    > > for all I know.
    > Which part exactly is unreliable. As far as I know, the standard 4.x
    > kernel contains working functions that write to the parallel port using
    > hardware assisted PIO or DMA. There is a hardware assisted PIO read
    > function that is broken, and there is no DMA read.

    Sorry, it's the DMA write that seems to be unreliable on some (at
    least two) machines. It might well be hardware bugs though.

    > I would be interested in integrating it into the parport_pc driver,
    > but have a few issues

    What are the issues?


    -- To unsubscribe, send mail to: --
    -- with the single word "unsubscribe" in the body of the message. --

    This archive was generated by hypermail 2b29 : Wed Oct 02 2002 - 06:15:02 EDT