Re: [PARPORT] Distro setup problem

Date: Sat Sep 30 2000 - 13:55:53 EDT

  • Next message: Tim Waugh: "Re: [PARPORT] Two printers, one parallel port"

    For now I'll declare this a distro problem and deal with it via a
    semi-kludge. If somebody feels like digging through the TurboLinux
    distro feel free. This is based on their 6.0.4 CDROM set. This uses
    the modular parport and parport_pc. What I've found is:

    1) parport_pc module correctly reports the PC parallel port hardware
     configuration via printk. So, the hardware recognition and setting of
     port->base_hi is correct.

    2) the parport structure returned by parport_enumerate() has the
     port->base_hi value set to zero.

    As far as I can tell there is no code anywhere in any parallel related
    module that modifies the parport struct after that configuration
    printk(). This leaves me with a mystery. Somewhere, somehow, something
    in that kernel is destroying that location. One guess is some sort of
    build problem. The base_hi is the last item in the structure. Maybe one
    of the routines was compiled with an older version?

    The workaround for me, since I don't feel like debugging an old kernel
    on an old distro, is adding a compile option to my driver: BROKEN_PCI,
    which redefines the ECONTROL and FIFO macros to compute addresses as
    offsets relative to base rather than base_hi. It breaks PCI boards,
    hence the name, but PCI boards are already rather broken on a system
    with this kernel bug.

    R Horn

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

    This archive was generated by hypermail 2b29 : Sat Sep 30 2000 - 14:01:55 EDT