* David Klann <dxklann@xxxxx> [2025-02-09 18:08]: > Hi, > > Long-time lurker, first time posting ... > > On 2/9/25 10:38 AM, Len Ovens wrote: > > On Sun, 9 Feb 2025, Peter P. wrote: > >> > >> I am running an Edirol UA-25 audio interface under jackd2. When I > >> disconnect the device with jackd running, it will print > > > > A long time ago, when jackd was designed, there were audio interfaces that > > would fit in one of the mother board slots. They were called ISA slots. > > These audio cards could only be removed when the beast was powered down. > > > > Jackd is a manually set up utility, it is told the device name at start > > and as such, it has no idea what to do when that device vanishes. It is > > possible with the tools supplied to tell jack to change it's device or > > backend while running via dbus. I have had varying amounts of success > > doing this after the USB device has been pulled. I would guess that > > because it is possible to change the device like this, jackdbus continues > > to run in hopes something else will happen. > > > > Basically, a device vanishing in an audio context is a system failure. USB > > might be designed for hot plugging but jackd is not. > > > > I use JACK in the (US) broadcast industry, mostly with Rivendell radio > automation (https://rivendellaudio.org/). > > After being frustrated at the "hot plug" nature of USB and the lack of > it with JACK I came up with a (pretty kludgy) workaround: using udev > rules and a simple shell script to add and remove jack clients from the > graph. > > With a rule like the one below for example (watch the wrap): > > # Focusrite Scarlett 4i4: 1235:8212 > ACTION=="add", ATTR{idVendor}=="1235", ATTR{idProduct}=="8212", > ENV{JACK_PROMISCUOUS_SERVER}="audio", > RUN+="/usr/local/bin/jack-reconnect -v -v USB Scarlett4i4-1" > > and the ZSH script at > https://github.com/opensourceradio/ram/blob/master/usr/local/bin/jack-reconnect > > one can "automatically" have one's Scarlett 4i4 (with USB ID 1235:8212) > connect and be inserted into the jack graph each time it is plugged in. > In case it's not obvious, this works only on Linux with a working udev > installation. Thanks David, nice to be reading your (first) post to this list! Your solution looks intriguing! I did not know that one can add devices to existing jack graphs, always thought that only software clients can connect to it(?). best, P _______________________________________________ Linux-audio-user mailing list -- linux-audio-user@xxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to linux-audio-user-leave@xxxxxxxxxxxxxxxxxxxx
