Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
Missed Keystrokes
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware
View previous topic :: View next topic  
Author Message
r00t440
Tux's lil' helper
Tux's lil' helper


Joined: 14 Sep 2005
Posts: 89

PostPosted: Mon Apr 01, 2013 4:05 pm    Post subject: Missed Keystrokes Reply with quote

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:
Quote:
Intel Core i7-2630QM
6 MB, 2.0 GHz
Intel HM65
802.11 b/g/n
FreeDOS
4 GB DDR3
14.0″ HD (1366×768) LED
Intel HD Graphics 3000
500 GB
DVDRW SuperMulti
10/100/1000 Mbps
2 x USB 2.0
Bluetooth 2.1
1.3 MP Camera
6-cell Smart Li-ion


Thanks in advance




** I've also posted this in: https://forum.sabayon.org/viewtopic.php?f=56&t=29577
Back to top
View user's profile Send private message
Budoka
Guru
Guru


Joined: 03 Jun 2012
Posts: 359
Location: Tokyo, Japan

PostPosted: Mon Apr 08, 2013 3:08 am    Post subject: Re: Missed Keystrokes Reply with quote

r00t440 wrote:
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:
Quote:
Intel Core i7-2630QM
6 MB, 2.0 GHz
Intel HM65
802.11 b/g/n
FreeDOS
4 GB DDR3
14.0″ HD (1366×768) LED
Intel HD Graphics 3000
500 GB
DVDRW SuperMulti
10/100/1000 Mbps
2 x USB 2.0
Bluetooth 2.1
1.3 MP Camera
6-cell Smart Li-ion


Thanks in advance




** I've also posted this in: https://forum.sabayon.org/viewtopic.php?f=56&t=29577

Are the letters that are getting dropped consistently the same? It could be something as simple as a dirty keyboard.
Back to top
View user's profile Send private message
verchiel
n00b
n00b


Joined: 25 Nov 2012
Posts: 15

PostPosted: Mon Apr 08, 2013 4:34 am    Post subject: Reply with quote

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.


Last edited by verchiel on Mon Apr 08, 2013 4:52 am; edited 2 times in total
Back to top
View user's profile Send private message
Budoka
Guru
Guru


Joined: 03 Jun 2012
Posts: 359
Location: Tokyo, Japan

PostPosted: Mon Apr 08, 2013 4:36 am    Post subject: Reply with quote

verchiel wrote:
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)?

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

Whoops. I missed that.
Back to top
View user's profile Send private message
verchiel
n00b
n00b


Joined: 25 Nov 2012
Posts: 15

PostPosted: Mon Apr 08, 2013 4:59 am    Post subject: Reply with quote

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. ^^
Back to top
View user's profile Send private message
r00t440
Tux's lil' helper
Tux's lil' helper


Joined: 14 Sep 2005
Posts: 89

PostPosted: Tue Apr 16, 2013 5:38 am    Post subject: Reply with quote

verchiel wrote:
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.


Wow, your guess is accurate. It's indeed a B5700N laptop. You must be from PH?

verchiel wrote:
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. ^^


No, backspace is working perfectly fine. With regards to disabling PS/2 keyboard in BIOS, I'm not sure if I can do that, laptops normally have limited options in BIOS that you can tweak. How is that different with using an external keyboard? I'm at work atm and I can't access my laptop so I'll try your suggestion when I get back home this weekend.

With regards to the idea of unplugging the keyboard, won't be a problem because it's already out of warranty. If it fails, then I think I'll just buy a Windows license.

Thanks Budoka and verchiel for taking the time to reply, I appreciate it - gives me some hope.

Cheers
Back to top
View user's profile Send private message
r00t440
Tux's lil' helper
Tux's lil' helper


Joined: 14 Sep 2005
Posts: 89

PostPosted: Thu May 23, 2013 6:18 am    Post subject: Reply with quote

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

Issue doesn't exist in Window$.

TIA
Back to top
View user's profile Send private message
teika
n00b
n00b


Joined: 19 Feb 2011
Posts: 68
Location: japan

PostPosted: Sat May 25, 2013 1:29 am    Post subject: Reply with quote

I'm completely clueless, but is it only in X, or in consoles, too?
Back to top
View user's profile Send private message
r00t440
Tux's lil' helper
Tux's lil' helper


Joined: 14 Sep 2005
Posts: 89

PostPosted: Sat Jun 08, 2013 4:45 pm    Post subject: Reply with quote

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
Back to top
View user's profile Send private message
Ant P.
Advocate
Advocate


Joined: 18 Apr 2009
Posts: 2333
Location: UK

PostPosted: Sat Jun 08, 2013 5:30 pm    Post subject: Reply with quote

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.
Back to top
View user's profile Send private message
r00t440
Tux's lil' helper
Tux's lil' helper


Joined: 14 Sep 2005
Posts: 89

PostPosted: Mon Jul 08, 2013 7:48 pm    Post subject: Reply with quote

Ant P. wrote:
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.


Hi Ant P. thanks for the idea, can this be configured during boot? - I'll google it. :D

Thanks
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum