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    Subjectkeyboard problem, again

    Again, sorry to bother you about this, but the problem with Toshiba's
    keyboard is real, and not only on my notebook, I confirmed this with
    other people on the net. Please, is anybody in charge with the
    keyboard code? Of course that code is supposedly working ok and
    probably it was forgotten - but see - this keyboard really has this
    annoying problem. Well - you might choose not to implement it in the
    kernel, but at least let me know about this so I can patch each and
    every kernel I install on the damn notebook by hand from this day


    From: Andrei Pitis <>
    Subject: Toshiba Satellite 2595XDVD
    Date: Wed, 1 Dec 1999 06:22:41 +0200 (EET)

    Hi everybody,

    I am not sure to whom should I address this, it's about a buggy
    keyboard controller (I guess) found on <subj> laptops that has a
    peculiar behavior with some key sequences. Specifically, when you
    press a shift (ctrl, alt, shift) and a key - (mostly when you play a
    lot with shifts, like in emacs :-)) - sometimes the controller ignores
    the repeat delay and repeats the key, sending very close (tens of
    miliseconds) key_down interrups (kbd MAKEs).

    Since this become very frustrating in time (imagine an emacs where
    meta or control sequences get out of hand) I have modified the
    handle_scancode function in drivers/char/keyboard.c to ack like a
    forced kbd delay. In other words, for each new (different from the
    previous one) scancode it sets up a delay (of 200 ms) in which it
    ignores the same scancode, if received within this window.

    I think this may as well be left there, I cannot think of things that
    might be broken by it, the second aparition of a scancode being
    always protected by the kdb delay (min 250 ms on PC kbds) - on sane PC
    kbds, at least... therefore the 200 ms does not do any harm to the
    normal kbds :-)

    Anyway, I would be grateful if the person in charge (Linus?) would be
    so kind to accept this patch, so I will not be doomed to patch by hand
    each and every kernel from now on :-))

    The code is as follows, and should be placed immediately after the
    variable declarations in the abovementioned function:

    * Begin patch for Toshiba Satellite 2595XDVD. Under some
    * circumstances, its keyboards behaves like ignoring the
    * kbd repeat delay. This happens in conjunction with shift
    * keys (ctrl, alt, shift) and leads to undesirable repeat
    * of a key even if pressed briefly. Fix it by ignoring any
    * subsequent occurence of the second identical scancode for
    * 200 ms. IMO, this doesn't break anything on a good keyboard.
    static int prev_scancode = 0;
    static int stop_jiffies = 0;

    /* new scancode, trigger delay */
    if (scancode != prev_scancode)
    stop_jiffies = jiffies;

    /* same scancode, accept only after the delay */
    else if (jiffies - stop_jiffies >= 20)
    stop_jiffies = 0;

    /* glitch! bail out... */

    prev_scancode = scancode;
    /* End Toshiba patch. */

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