Ubuntu
linux-source-2.6.15 package

PS/2 keyboard broken by "legacy USB keyboard" option in BIOS

Bug #48877 reported by Guillaume Savaton on 2006-06-07

This bug report is a duplicate of: Bug #83066: no ps/2 keyboard with kernel 2.6.15-27-686-smp. Edit Remove

Affects		Status	Importance	Assigned to	Milestone
	linux-source-2.6.15 (Ubuntu)	New	High	Unassigned

Bug Description

This bug was detected at the first reboot after upgrading from Breezy to Dapper 6.06.
My computer is a desktop PC (motherboard ASUS P4PE-X) with an ordinary PS/2 keyboard and a USB mouse.

Typical scenario :
- No error during reboot.
- The GDM login screen appears
- Typing in the username text field has no effect at all.
- Num lock and Caps lock keys have no effect on the keyboard LEDs.

When booting in "recovery mode", there is no keyboard input in the console either.

I tried to investigate the problem remotely by connecting another PC to my Ubuntu box through SSH.
Results : all logs seem to be fine.

I solved the problem by blacklisting the "psmouse" kernel module in /etc/modprobe.conf/blacklist

I found this solution in an old thread at the following address :
http://www.ussg.iu.edu/hypermail/linux/kernel/9706.2/0162.html

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Guillaume Savaton (gsavaton-deactivatedaccount) wrote on 2006-06-09:

Well, the "solution" did not work as well as I thought.
The problem reappeared after a second reboot.

It seems that psmouse is not related to my problem at all.

Sometimes, keyboard input becomes effective after "a certain time" after rebooting.
But today, my computer was powered on all day long, displaying only the GDM login screen, and the keyboard did never work.

A last precision : mouse input works perfectly in GDM : I can play with the menu, reboot, etc.

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Guillaume Savaton (gsavaton-deactivatedaccount) wrote on 2006-06-09:

Here is another thread about a similar problem.
The proposed solution consists in booting with ACPI off.

http://www.ussg.iu.edu/hypermail/linux/kernel/0205.3/0397.html

It works, at last !

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Guillaume Savaton (gsavaton-deactivatedaccount) wrote on 2006-07-15:

With kernel 2.6.15-26-686 the problem persists.

Of course, booting with ACPI off allows me to use my PS/2 keyboard.
But I would really like to be able to use ACPI again : one reason is that I want to benefit from the hyperthreading capabilities of my processor, which are currently unused.

Can anyone clarify the relationship between PS/2 keyboards, ACPI and hyperthreading ?

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James Cuzella (trinitronx) wrote on 2006-09-12: Breakthrough Perhaps?

my current xorg.conf file Edit (5.5 KiB, text/plain)

I have been having this bug off and on ever since using Ubuntu Breezy (pretty sure it happens in both 386 and 686... but since it's so random, and since I never really boot 386, I can't tell). I just found what I think to be a breakthrough while booting up my PC today.

I started my machine up, and watched it get to the familiar gdm login screen which will decide my keyboard input's fate for the session. Again, I was greeted with the familiar sign that my keyboard was not going to work again: the num lock light was lit after the boot process finished and brought me to gdm. Absolutely no keyboard input does anything while it's in this zombie state. Then, I decided that I've been sick of this for so long that I'd try unplugging my keyboard again to no avail. Then, I realized that I had never actually tried plugging my PS/2 keyboard into my Dell PC's other PS/2 port (the one that's labelled on the back for use with a mouse). To my surprise, my keyboard was working again!!

I sit here typing this with the keyboard plugged into the mouse PS/2 port! Luckily my mouse is not a PS/2 mouse, but a USB optical mouse ;), so I do have mouse input as well.

I also just tested a PS/2 mouse in the keyboard port, but the port itself is zombified... I can plug my keyboard in, it gets power of course, but no input is taken. Maybe an off by 1 bug?

Hopefully useful info:
Computer: Dell XPS Desktop Generation 2
Processor: Pentium 4 3.2GHz w/ Hyperthreading
Mobo: Dell-ified intel i875p chipset
Keyboard: standard Dell brand PS/2 keyboard
Mouse: Razer Copperhead USB mouse
OS: Ubuntu Dapper Drake 6.06 LTS
Kernel: 2.6.15-26-686
xorg.conf included as attachment

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Guillaume Savaton (gsavaton-deactivatedaccount) wrote on 2006-09-12: Re: PS/2 keyboard does not work

I finally found a working solution to the problem :
I disabled the "legacy USB keyboard" option in my BIOS.

It is still not clear to me why this option should prevent the use of a PS/2 keyboard.

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Tassos Bassoukos (abassouk) wrote on 2006-10-31:

Same issue here, solved by disabling "legacy keyboard support" in the BIOS. Award BIOS version 6.00PG, if it is of any use.

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P Wagner (pwagner) wrote on 2006-12-29:

I have experienced the same issue with the HP Media Center PC m7674n that was just purchased. Wanted to upgrade to Ubuntu Edgy and wasn't able to as there was no response from the PS/2 keyboard and mouse. Extra/backup USB mouse works but only have PS/2 keyboards... Disabled the PS/2 mouse port, still didn't work. No legacy option in my bios options!

Any help/ideas?