[PARPORT] Re: amiga printing problems

From: Ken Tyler (kent@werple.net.au)
Date: Fri Aug 31 2001 - 08:59:07 EDT

  • Next message: Roman Zippel: "[PARPORT] Re: amiga printing problems"

    On Thu, 30 Aug 2001, Roman Zippel wrote:

    > Let's try my suspicion. :)
    > Could you disable this part in
    > drivers/parport/ieee1284_ops.c:parport_ieee1284_write_compat():
    > /* Is the peripheral ready yet? */
    > if (!parport_wait_peripheral (port, mask, val))
    > /* Skip the loop */
    > goto ready;
    > IMO this should already help a bit, although there might be new
    > problems.


    No good at all, nothing prints. A bit of debug added shows it to be stuck
    in the

    do { ... } while (time_before (jiffies, expire));

    > Second, you can simply remove the call to parport_enable_irq(), the irq
    > is never disabled, so it doesn't need to be enabled all the time. This
    > will get rid of the kernel warnings.

    OK, a minor problem at the moment ;)

    > > I can't see anything in parport_amiga.c in combination with ieee1284_ops.c
    > > that supports a write -> strobe -> ack -> interrupt -> do it again loop.
    > Because it's automatically handled in the hardware, otherwise it had to
    > happen in the write_control function.

    Sorry, I wasn't very clear. I know it's done in hardware, write a byte to
    the CIA which STOBES the printer, ACK comes back from the printer and
    generates a CIA FLAG interrupt.

    I can't see / understand how parport_ieee1284_write_compat and the
    wait/poll functions it calls wait for the ACK interrupt to comeback before
    sending the next byte out.


    -- To unsubscribe, send mail to: linux-parport-request@torque.net --
    -- with the single word "unsubscribe" in the body of the message. --

    This archive was generated by hypermail 2b29 : Fri Aug 31 2001 - 12:47:06 EDT