Should recover from OP-Z disconnect

[xmacex]

If the OP-Z disconnects e.g. by removing cable or turning it off while this thing is enabled, the alsa_in process is left confused and start producing errors fast. This slows down norns, so this event needs to be recovered from. udev rules would make so much sense, rather than having a program like this in the first place.

[xmacex]

When the OP-Z setup is active, and the device is disconnected by pulling the cable

Nov 02 01:18:39 norns connect-opz.sh[11067]: selected sample format: 24bit - real
Nov 02 01:18:39 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:39 norns connect-opz.sh[11067]: Write error: No such device
Nov 02 01:18:39 norns kernel: usb 1-1.2: USB disconnect, device number 4
Nov 02 01:18:39 norns connect-opz.sh[11067]: selected sample format: 24bit - real
Nov 02 01:18:39 norns connect-opz.sh[11067]: delay = 2900
Nov 02 01:18:39 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:39 norns jackd[319]: JackEngine::XRun: client = crone was not finished, state = Triggered
Nov 02 01:18:39 norns jackd[319]: JackEngine::XRun: client = softcut was not finished, state = Triggered
Nov 02 01:18:39 norns jackd[319]: JackEngine::XRun: client = SuperCollider was not finished, state = Triggered
Nov 02 01:18:39 norns jackd[319]: JackEngine::XRun: client = alsa_out was not finished, state = Running
Nov 02 01:18:39 norns jackd[319]: JackEngine::XRun: client = alsa_in was not finished, state = Running
Nov 02 01:18:39 norns jackd[319]: JackAudioDriver::ProcessGraphAsyncMaster: Process error

Loads of that. Then

Nov 02 01:18:50 norns jackd[319]: JackAudioDriver::ProcessGraphAsyncMaster: Process error
Nov 02 01:18:50 norns jackd[319]: JackEngine::XRun: client = crone was not finished, state = Triggered
Nov 02 01:18:50 norns jackd[319]: JackEngine::XRun: client = softcut was not finished, state = Triggered
Nov 02 01:18:50 norns jackd[319]: JackEngine::XRun: client = SuperCollider was not finished, state = Triggered
Nov 02 01:18:50 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:50 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:50 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:50 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:50 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:51 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19
Nov 02 01:18:52 norns connect-opz.sh[11067]: err = -19

Quite a bit of that too. Then

Nov 02 01:19:09 norns connect-opz.sh[11067]: err = -19
Nov 02 01:19:09 norns connect-opz.sh[11067]: err = -19
Nov 02 01:19:09 norns systemd-journald[98]: Suppressed 7882 messages from /system.slice/norns-jack.service
-- Subject: Messages from a service have been suppressed
-- Defined-By: systemd
-- Support: https://www.debian.org/support
-- Documentation: man:journald.conf(5)
--
-- A service has logged too many messages within a time period. Messages
-- from the service have been dropped.
--
-- Note that only messages from the service in question have been
-- dropped, other services' messages are unaffected.
--
-- The limits controlling when messages are dropped may be configured
-- with RateLimitIntervalSec= and RateLimitBurst= in
-- /etc/systemd/journald.conf. See journald.conf(5) for details.
Nov 02 01:19:09 norns jackd[319]: JackEngine::XRun: client = crone was not finished, state = Triggered
Nov 02 01:19:09 norns jackd[319]: JackEngine::XRun: client = softcut was not finished, state = Triggered
Nov 02 01:19:09 norns jackd[319]: JackEngine::XRun: client = SuperCollider was not finished, state = Triggered
Nov 02 01:19:09 norns jackd[319]: JackEngine::XRun: client = alsa_in was not finished, state = Triggered

And so on. Restarting systemd service norns-jack, or killing it's jackd does not help the flood of -19s. I haven't found another way besides rebooting.