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-   -   Keyboard delay in ttys (from 2.6.28-16-generic to on Ubuntu 9.04 Jaunty) (

fsantandrea 11-15-2009 09:48 AM

Keyboard delay in ttys (from 2.6.28-16-generic to on Ubuntu 9.04 Jaunty)
Greetings to everyone.

I have recently started a Linux kernel hacking course at university. So I enjoyed taking a closer look at kernels, and decided I wanted to have the latest kernel on my Ubuntu.

So I downloaded from I configured it by copying the default 2.6.28-16-generic config that comes in the Ubuntu kernel package, doing `make oldconfig` and answering new question ALL with the defaults.

Compiled it and installed it -- it works like a charm. Everything is as before, if not better. However.

I seem to have a strange delay problem with terminals.

If I open a terminal and start writing, my keyboard input hangs for exactly for 1/4 of second every two seconds, and then everything I typed in that 1/4 second shows up all at once.

As a clarifying example: if I keep the `T` key pressed, it repeats as normal, but every 2 seconds it seems to stop for a 1/4 second, after which all the `T`s which would have been printed in that time are printed all at once.

I have this problem every time I type into a terminal, be it gnome-terminal, xterm, or even the CTRL+ALT+F1 console. But this does NOT happen if I type in GUI applications. For example, if I type in Firefox or gedit, everything works ok. It's just ttys that have this problem. Also, programs writing on standard output don't hang like that - only input does. Killing X doesn't help.

Booting with the old kernel removes the problem. So this looks like a new kernel feature that my hardware doesn't like.

Anyone that successfully addressed the same problem?

Thank you very much.

nonoitall 12-31-2009 01:28 AM

I have this problem on Karmic with the stock kernel. Ever find a good solution?

fsantandrea 01-01-2010 07:30 AM

Well, actually I just gave up the idea and reinstalled the "old" stock kernel.
I guess a subsequent patch will someday fix the problem, which maybe is specific to our platform.

Meanwhile, I hope I won't miss too much. :)

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