[BRLTTY] HID slowness

[Sébastien Hinderer]

Hello,

Yannick and I happened to meet at one of our national distributor's
office. We tested an eMotion device from HIMS whichwe found rather nice,
ergonomically speaking.

In terms of USB connectivity, two modes of connection are supported:
legacy and HID. Although both modes do work with BRLTTY, we noticed
that, in HID mode there is considerably more latency than in USB legacy
mode. For example, the round-trip time between a keypress and the
corresponding update of the braille display nears the second while it is
much shorter in USB (without being of great reactiveness but we think
this is an internal problem).

Any suggestion on what could be done to improve the situation?

Best wishes,

Seb.