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Date:      Wed, 22 Feb 2006 11:47:33 +0100
From:      "Norbert Koch" <NKoch@demig.de>
To:        <freebsd-hackers@freebsd.org>
Subject:   does ukbd delay break scan codes?
Message-ID:  <000001c6379d$63036d80$4801a8c0@ws-ew-3.demig.intra>

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Hello,

while testing an older release
of kbdmux under FreeBSD4 I am
seeing some strange things:

I have attached a primary
ps/2 and a secondary usb keyboard.
I run under X (which means that kbdmux
is switched to return raw key codes only)
and inspect kbdmux using some printfs
and xconsole.

>From time to time I 'freeze' the keyboard
input of my X application by pressing
e.g. Ctrl+Fn1 on the primary keyboard.
I still see kbdmux returning scan codes.
Unfreezing can be done by simply
switching virtual consoles, which seems
to somehow re-initialize the keyboard state.

I still do not know where it comes from,
but what I found so far is,
that the usb keyboard (or ukbd driver)
seems to delay the break codes for
keys with prefix E0 (which may or may not
have anything to do with my problem).

E.g., I press Keypad-Enter and see
  E0 1C E0
        ^prefix
     ^make code
  ^prefix
and nothing else. As soon as I press
e.g. Enter (any key works) I see
  9C 1C 9C
        ^break code
     ^make code
  ^delayed break code.

Does anyone have an idea where that
may come from?
Could it be a possible bug in ukbd's
conversion code?
(BTW: I compared ukbd.c of RELENG-4
 against RELENG-6. There are no
 significant differences)
My usb keyboard is a Cherry RS6000.

Norbert



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