[BRLTTY] Brailliant BI sticky input

[Mario Lang]

Stéphane Doyon <s.doyon at videotron.ca> writes:

> On Tue, 24 Mar 2015, Mario Lang wrote:
>
>> Stéphane Doyon <s.doyon at videotron.ca> writes:
>>
>>> I'm having a strange and annoying issue with my Brailliant BI 40,
>>> where brltty seems to think some navigation keys get stuck.
>>
>> I know that issue.  It has been fixed for me with BRLTTY 5.2.
>
> You do? It has? Interesting.

I should explain that I am not using a Braillain BI 40, but a Brailliant
B 80.  But I have noticed the issue of "loosing keypresses
non-deterministicly" on the first day that I tested the Brailliant.  I
too, as you, originally thought it might be a hardware issue.  However,
while the hardware was not changed, the issue went away with a certain
revision (not bisected) of BRLTTY.  I think Dave can explain this more
in detail, but the guess back then was, that the host doesn't always get
the pending input early enough.  Something about an USB chip with very
little input buffering.  While this issue was fixed on my particular host,
it could be that you still have certain timing issues on your side which
makes this bug reappear on your host.  What type of host are you using,
speed-wise?  A stock 64-bit desktop or some sort of embedded ARM?
Have you tried to use Bluetooth.  I don't remember exactly, but from
what I know about this issue, it should be USB-specific.

>> What version of BRLTTY are you using?
>
> I upgraded to the latest earlier this week in hopes of seeing this
> issue go away. Changed my USB cable too :-). But no luck.

Since this is fixed on my side these days, I have nothing useful to
say.  Maybe Dave can step in with some insight on the current state of
async IO.

-- 
CYa,
  ⡍⠁⠗⠊⠕