[PARPORT] Re: Printing to off-line printer in 2.4.0-prerelease

From: Peter Osterlund (peter.osterlund@mailbox.swipnet.se)
Date: Wed Jan 03 2001 - 20:09:56 EST

  • Next message: Andrea Arcangeli: "[PARPORT] Re: Printing to off-line printer in 2.4.0-prerelease"

    On Thu, 4 Jan 2001, Andrea Arcangeli wrote:

    : I'm worried somebody needed to disable LP_CAREFUL to print, probably
    : it's not a big deal to keep it.

    I removed it because otherwise I would have had to do twice as many tests
    to convince myself that all combinations of flags and printer states
    worked correctly. I can reinsert it if you think that's necessary. But
    then I don't think the tunelp man page and the comments in the kernel
    should say that it is obsolete. I think obsolete means "you should never
    ever have to use this stuff".

    : However parport_write can still could silenty discard data, but maybe
    : it can't notice errors with some handshake.

    At least with my printer, it only discards data when it is powered off. If
    you power off the printer between the times when lp_wait_ready returns and
    parport_write is called, I think it is ok to lose data. After all, if the
    power off had occurred a few ms later, the data would already have been in
    the printer when it was powered off, and then you would have lost data

    : I didn't checked the details of the DMA based handshake so Tim needs
    : to comment if this can be considered a final/right fix (I hope it's
    : not ;).

    I don't understand the lowlevel parport details, so I can not comment on

    Peter sterlund             peter.osterlund@mailbox.swipnet.se
    Skndalsvgen 35            http://home1.swipnet.se/~w-15919
    S-128 66 Skndal            +46 8 942647

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