Deadlock or race condition preventing disposal if headstage never produces frames

[jonnew]

I'm dealing with a pretty nasty issue in which the hardware is left in a complete broken state in some circumstances. The issue seems to stem from a situation in which a headstage is locked and matches the configuration (shows up in device table etc), but, for whatever reason, never produces a frame. This leads to a series of failures

• Stopping bonsai: hardware is left in running state
• Closing bonsai: ports remain on and locked

This situation appears to result in infinite loop until complete power cycle of the ONIX hardware indicating some interplay between the context configuration and software locking and disposal sequences.

If I go into oni-repl and manually turn off all ports, make sure that the context is in non-passthrough mode, etc, then i can recover functionality.

Clearly this is non optimal. there should be a catch all at both Start and Stop actions that completely reset ONIX hardware.

[jonnew]

To be honest @aacuevas I think this is actually equally on software and hardware. The problem with register values that are unaffected by a reset is that there is no easy way to get the hardware to default state in catastrophic situations. It makes we want a secondary reset signal, reset_hard that brings all device registers to power-on default.

[jonnew]

This may be fixed by #409. It can be reopened if the problem persists.