Re: [PARPORT] Parallel ZIP drive problem.

From: Tim Waugh (twaugh@redhat.com)
Date: Sun Jul 02 2000 - 05:57:21 EDT

  • Next message: Gunther Mayer: "[PARPORT] Patch[2.4.0pre3t2]: Parport TSC Timings"

    On Sat, Jul 01, 2000 at 04:59:02PM -0400, E. Charters wrote:

    > They don't work in windows either on a lava port as I recall.

    Really? I'd be surprised.

    I think there is probably a timing problem with the Zip drive driver:
    this would show up on PCI parallel port cards because they are so much
    quicker than on-board cards (PCI latency instead of ISA latency).

    I suspect that there are at least two places in the driver where this
    problem shows up: one where the udelay patch goes, and one somewhere
    else. There are quite possibly several places too. :-(

    Other than trial and error, I'm not sure how to go about fixing it
    properly: David Campbell is out of contact still, so unless Grant has
    some spare time(?) it looks like someone might need to do a bit more
    reverse engineering.

    What might work is giving ppa/imm back the module parameter for
    forcing a particular transfer mode. I'm not sure

    a) whether to do this as a parport option
    b) whether to do it as a ppa/imm option instead
    c) whether to do this in 2.2, 2.4 or 2.5
    d) whether to do it at all if leaving it out will get the problem
       fixed properly quicker.

    Comments?

    Tim.
    */



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