Re: [PARPORT] parport time outs with 2.4.0-test9

From: Tim Waugh (
Date: Sat Nov 11 2000 - 07:33:49 EST

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    On Fri, Nov 10, 2000 at 02:17:08PM +0100, Thomas Roessler wrote:

    > [Please CC me upon replies, since I'm not subscribed to the
    > linux-parport mailing list. I did check the archive, though.]

    When reporting problems with parport, really you need to give all of
    the messages that parport_pc spits out when it initialises. There are
    several code paths:

    o polling
    o interrupt-driven, protocol in software
    o interrupt-driven, protocol in hardware using PIO
    o interrupt-driven, protocol in hardware using DMA

    For normal printer protocol, having IEEE 1284 modes enabled or not
    should not make a difference.

    To turn off the 'protocol in hardware' code paths, disable
    CONFIG_PARPORT_PC_FIFO. Note that when they are enabled they are not
    necessarily _used_; it depends on whether the hardware is available,
    enabled by the BIOS, and detected by the driver.

    So, to start with, disable CONFIG_PARPORT_PC_FIFO, and load parport_pc
    with 'irq=none'. See if the printer stalls when you print stuff.

    If that works fine, try with 'io=0x378 irq=7' (adjust for your
    hardware), to make it use interrupt-driven in-software protocol.

    If _that_ works fine, then one of the hardware modes isn't working
    right. Enable CONFIG_PARPORT_PC_FIFO (no, it isn't a module option,
    and yes, it should be), set the port to ECP mode in the BIOS and note
    the DMA channel, and try with:

        io=0x378 irq=7 dma=none (for PIO)
        io=0x378 irq=7 dma=3 (for DMA)

    Let me know the results.


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