Re: [PARPORT] Difference between PPNEGOT and PPSETMODE?

From: Tim Waugh (twaugh@redhat.com)
Date: Mon Feb 05 2001 - 11:51:52 EST

  • Next message: Mohammed El Shobaki: "[PARPORT] Difference between PPNEGOT and PPSETMODE?"

    On Mon, Feb 05, 2001 at 05:41:16PM -0800, Mohammed El Shobaki wrote:

    > We have a problem with negotiating to EPP (or any other mode except COMPAT)
    > using the PPNEGOT command (returns -1). However, if we run PPSETMODE for
    > the same mode(s) as arguments it succeeds. The question is, what's the
    > difference between NEGOT and SETMODE?

    NEGOT does a full IEEE 1284 negotiation from whatever mode the kernel
    state machine thinks you're in to whatever mode you tell it to go to.

    SETMODE just jumps the kernel state machine straight to your chosen
    mode without even so much as tell the device about it.

    So, if your device expects to speak ECP from the moment it is switched
    on, you want to use SETMODE. If, however, it implements a full IEEE
    1284 state machine itself and is expecting to be told what mode to
    use, you want NEGOT.

    Tim.
    */



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