Missed Keystrokes

[r00t440]

I have a cheap laptop with an unknown brand, there seems to be a problem with the way it handles keyboard input.

Here's how it behaves:

When typing it seems to sporadically skip characters. Example, if I type "Hello" there's a chance that the entered text just becomes "Hllo". I tried the following without luck:

* Different distros - I tried SystemRescueCD; Funtoo; Ubuntu; Different flavors of Sabayon
* An external USB keyboard
* Toggling ACPI during boot and some IRQ tricks I found from other forums

Some success:

Few months back, the symptom doesn't seem to exist on 32-bit Sabayon (64-bit versions always have the problem), however after several updates (also updated the kernel), the symptom re-emerged. In windows everything works fine so my guess is that this laptop uses some sort of low quality "keyboard controller" - not sure what's the term. It seems that its "input buffer" is buggy - at least on 64bit Linux.

I hope somebody can point to me which kernel option I should check or experiment with - I am comfortable to compiling the kernel (been doing it for like 10 years already). Probably some kernel options cause this behavior.

Laptop Specs:

[Budoka]

[verchiel]

Well, r00t440 claimed to have tried an external keyboard, so dirt in the keyboard shouldn't be an issue. I would rather check the BIOS settings again and look for anything keyboard related as well as USB settings. Can you tell us your BIOS name/version (and maybe search for known issues as well)? And maybe be so kind and look for information on the mainboard and/or vendor information on the laptop, even if the brand is less well-known... what is its name anyway (model/vendor)? Or, if that information is unavailable, where did you buy it / do you have a link to the product? If it is really an OS problem then I'd rather guess it's about the mainboard/chipset. In many cases laptop keyboards are connected through PS/2 ports rather than USB though. Are you experiencing any other issues?

Cheers
Dan

Addendum: From the information you provided, it sounds pretty much like a Basic B57xx series model from the Neo brand. Just a guess.

[Budoka]

[verchiel]

And just another guess... the backspace key might be malfunctioning. You could try disabling your PS/2 keyboard in the BIOS setup and see if it works fine if you use only your USB keyboard instead. Just another guess. And if there is no such option... well, I have to hint you that it might mean losing warranty, but I would open the laptop and unplug the keyboard. Or even unsolder if necessary. I don't recommend that though. ^^

[r00t440]

[r00t440]

Unable to solve this problem. I hope somebody out there can shed some light with this issue.

Issue doesn't exist in Window$.

TIA

[teika]

I'm completely clueless, but is it only in X, or in consoles, too?

[r00t440]

Hi teika, thanks for replying.

I'm clueless as well, all I have are symptoms of the problem. I think the best way forward is to just live with this issue, I'm thinking of utilizing this notebook as an HTPC.

Kind regards

[Ant P.]

Does this happen if you temporarily disable some of the extended powersaving features? I've seen similar things happen on an AMD CPU with C1E enabled and a Celeron with CONFIG_NO_HZ.

[r00t440]