[BRLTTY] BRLTTY with keytable enabled sometimes locks keys

[Nicolas Pitre]

On Sun, 13 Jul 2014, Sebastian Humenda wrote:

> Dave Mielke schrieb am 11.07.2014, 18:06 -0400:
> 
> >Are you saying that pressing caps lock - which you've redefined to be escape 
> >and expect to be escape - is still acting as caps lock, or are you saying that 
> >caps lock seems to just go on for no obvious reason?
> In a way the latter: Caps lock is suddenly activated and cannot be deactivated:
> 
> 1.  Before logging in, caps lock  is still caps lock, this is changed when
>     logging in. In very rare cases, all numbers occur as if I had pressed them
>     with a shift key. All letters are still lower case, but the numbers are
>     gone. Neither with or without shift brings them back, I get only the special
>     characters. Pressing caps lock doesn't change that either.
> 2.  When logged in, caps lock is replaced through escape, since caps lock is a
>     key I don't like. BRLTTY works with this redefined key nevertheless. When I
>     restart BRLTTY for whatever reason, it happens (again rarely), that caps
>     lock is activated, I cannot switch TTY's and the key cannot be deactivated.
>    
> >What you're describing is very odd since there's ultimately no difference 
> >between the handling of keyboard events and the handling of braille device key 
> >events.
> Is there no difference between retrieving keyboard key presses from the kernel
> and receiving device key presses? Maybe it's a bug elsewhere?

It happened to me very rarely that a braille key press is never 
released, or more likely that the release event was lost.  This is 
always on my laptop and not on my faster desctop PC. And only when 
connected over USB.

On that laptop I don't use keyboard keymaps because normal key presses 
will get into auto-repeat mode occasionally even if I don't hold them 
down. This manifests itself as some repeated characters when typing 
which is very annoying.  I suppose this is due to the key release event 
not forwarded back quickly enough in those cases e.g. before the 
auto-repeat delay managed by the kernel expires.

At least on this laptop, keyboard key management appears more 
difficult than device key management.


Nicolas