[gentoo-user] serio / atkbd / PS/2 Strangeness with Serial port adapter

[Matt Causey]

Hello!

Apologies if this really is't the right forum (suggestions on the
right forum would be welcome).

Our company presently operates a large number of thin client terminals
running LTSP, with a shared NFS root filesystem, and all that stuff.
To remove the external runtime dependencies from the image, I've built
a gentoo ramdisk that contains all the tools needed for the terminals
- which can be downloaded via tftp.

Things are working well - except for one problem.  One the new image,
some of the input devices don't work we expected.  As you might
imagine in a production environment, we have a number of different
barcode scanners that attach to these terminals.  Many of the new ones
are USB HID compliant devices - which is great.  Most of them are
actually serial port devices, that connect to the terminal via a
serial --> PS/2 'wedge'.  The PS/2 wedge devices are the ones that
don't work correctly.

If we connect the scanner to the thin client, and boot the image, the
scanner does not work.  It does not show up at all as an input device:

blablahostname / # cat /proc/bus/input/devices
I: Bus=0003 Vendor=046d Product=c001 Version=0110
N: Name="Logitech USB Mouse"
P: Phys=usb-0000:00:03.0-1/input0
S: Sysfs=/devices/pci0000:00/0000:00:03.0/usb2/2-1/2-1:1.0/input/input0
U: Uniq=
H: Handlers=mouse0 event0
B: EV=17
B: KEY=70000 0 0 0 0 0 0 0 0
B: REL=103
B: MSC=10

I: Bus=0003 Vendor=03f0 Product=0024 Version=0110
N: Name="CHICONY HP Basic USB Keyboard"
P: Phys=usb-0000:00:03.1-2/input0
S: Sysfs=/devices/pci0000:00/0000:00:03.1/usb3/3-2/3-2:1.0/input/input1
U: Uniq=
H: Handlers=kbd event1
B: EV=120013
B: KEY=10000 7 ff9f207a c14057ff febeffdf ffefffff ffffffff fffffffe
B: MSC=10
B: LED=7

I: Bus=0010 Vendor=001f Product=0001 Version=0100
N: Name="PC Speaker"
P: Phys=isa0061/input0
S: Sysfs=/devices/platform/pcspkr/input/input2
U: Uniq=
H: Handlers=kbd event2
B: EV=40001
B: SND=6

So, I enabled debugging on the contoller driver(serio.c), and I see
that the device generates noise when connected:

[  458.875614] drivers/input/serio/i8042.c: f2 -> i8042 (kbd-data) [444989]
[  458.908119] drivers/input/serio/i8042.c: fe <- i8042 (interrupt, 0,
1, timeout) [445022]
[  458.908144] drivers/input/serio/i8042.c: ed -> i8042 (kbd-data) [445022]
[  458.940151] drivers/input/serio/i8042.c: fe <- i8042 (interrupt, 0,
1, timeout) [445054]
[  458.940225] drivers/input/serio/i8042.c: d4 -> i8042 (command) [445054]
[  458.940234] drivers/input/serio/i8042.c: f2 -> i8042 (parameter) [445054]
[  458.972190] drivers/input/serio/i8042.c: fe <- i8042 (interrupt, 1,
12, timeout) [445086]
[  458.972204] drivers/input/serio/i8042.c: d4 -> i8042 (command) [445086]
[  458.972212] drivers/input/serio/i8042.c: ed -> i8042 (parameter) [445086]
[  459.004227] drivers/input/serio/i8042.c: fe <- i8042 (interrupt, 1,
12, timeout) [445118]
[20171.684870] drivers/input/serio/i8042.c: 0b <- i8042 (interrupt, 0,
1) [20162195]

However - the atkbd driver does not pick the device up at all.

So, I did find a workaround (which is NOT acceptable for this
deployment).  Remember the PS/2 'wedge' I mentioned?  Well, it has an
extra PS/2 port for your keyboard.  If I connect a PS/2 keyboard to
that thing, suddenly my scanner starts working.

We see some chatter from the controller driver, then one of these:

[23811.805578] input: AT Translated Set 2 keyboard as
/devices/platform/i8042/serio0/input/input6

Aaaand a new device is registered as an input device:

yayayayhostname# cat /proc/bus/input/devices
I: Bus=0003 Vendor=046d Product=c001 Version=0110
N: Name="Logitech USB Mouse"
P: Phys=usb-0000:00:03.0-1/input0
S: Sysfs=/devices/pci0000:00/0000:00:03.0/usb2/2-1/2-1:1.0/input/input0
U: Uniq=
H: Handlers=mouse0 event0
B: EV=17
B: KEY=70000 0 0 0 0 0 0 0 0
B: REL=103
B: MSC=10

I: Bus=0003 Vendor=03f0 Product=0024 Version=0110
N: Name="CHICONY HP Basic USB Keyboard"
P: Phys=usb-0000:00:03.1-2/input0
S: Sysfs=/devices/pci0000:00/0000:00:03.1/usb3/3-2/3-2:1.0/input/input1
U: Uniq=
H: Handlers=kbd event1
B: EV=120013
B: KEY=10000 7 ff9f207a c14057ff febeffdf ffefffff ffffffff fffffffe
B: MSC=10
B: LED=7

I: Bus=0010 Vendor=001f Product=0001 Version=0100
N: Name="PC Speaker"
P: Phys=isa0061/input0
S: Sysfs=/devices/platform/pcspkr/input/input2
U: Uniq=
H: Handlers=kbd event2
B: EV=40001
B: SND=6

I: Bus=0011 Vendor=0001 Product=0001 Version=ab41
N: Name="AT Translated Set 2 keyboard"
P: Phys=isa0060/serio0/input0
S: Sysfs=/devices/platform/i8042/serio0/input/input6
U: Uniq=
H: Handlers=kbd event3
B: EV=120013
B: KEY=4 2000000 3803078 f800d001 feffffdf ffefffff ffffffff fffffffe
B: MSC=10
B: LED=7

So, I don't get it.  We had this all working fine with the (now
ancient version) LTSP configuration, linux 2.4, etc.  Did some drastic
things change in 2.6 with keyboard management?

I am completely out of ideas.  The only thing I can figure is that the
PS/2 wedge thing isn't doing the right thing, and as a result the 2.6
version of the atkbd driver isn't binding it?   Maybe there is some
udev magic I need to know?  Maybe the serio controller driver isn't
doing the right thing?

I'm fairly new to Gentoo - so apologies if I've missed something
obvious here.  Any help would be much appreciated - because I'd really
like for this Gentoo image to work out.

Thanks!

--
Matt