Bug#857559: unblock: brltty/5.4-7

[Niels Thykier <niels@thykier.net>]

Samuel Thibault:
> Package: release.debian.org
> Severity: normal
> User: release.debian.org@packages.debian.org
> Usertags: unblock
> 
> Hello,
> 
> As documented in Bug#857558, the blind users which use Vario Ultra
> devices (which are becoming more and more popular) report that if they
> type too fast, brltty restarts its driver, thus incurring a spurious
> delay, which prevents from working for several seconds while the restart
> is done, thus making working very tedious, and thus Vario Ultra unusable
> with Debian.
> 

Hi,

Ack from me; CC'ing KiBi for a d-i ack (leaving the mail quoted in for
his convenience).

> We have investigated with upstream, what happens is that the device
> is very slow to send key press events, and it's easy to actually type
> faster than what the device can send, and in that case the device does
> not even have the opportunity to acknowledge the braille output updates
> that brltty sends, and thus brltty gets impatient and restarts the
> driver.  There is nothing we can really do about it, the device is just
> too slow, so in the attached uploaded changes, upstream has made the
> driver ignore time out errors. This was tested by various Vario Ultra
> users.
> 
> Additionally, as documented in Bug#854295, it seems espeak-ng crashes
> while being used by brltty. What we found is that this happens because
> of a callback that brltty sets to follow the progress of the speech
> synthesis.  In the attached uploaded change, I have just disabled this
> feature (which is not really used by users, only for demos), which
> avoids the encountered crashes.  We'll have to see with upstream brltty
> and espeak-ng how this can be properly fixed, but that will probably be
> quite involved, while we can just disable this feature for Stretch.
> 
> Samuel
> 
> unblock brltty/5.4-7
> 
> [...]


~Niels