What is the problem?
While running a long print last night, it suddenly just froze the printer. When checking the logs, the only thing occurring at the time, from syslog, was the rngd daemon gathering entropy. Is there a way to disable /dev/random or /dev/hwring to leave the /dev/TTYUSB0 driver alone to see if this could have been the cause?
What did you already try to solve it?
Lots of google searches
Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)
Apr 3 00:40:00 dave-octopi kernel: [35407.931658] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
Apr 3 00:40:00 dave-octopi kernel: [35407.931910] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
Apr 3 00:41:50 dave-octopi kernel: [35517.940310] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
Apr 3 00:41:50 dave-octopi kernel: [35517.940562] ch341-uart ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
Apr 3 00:41:50 dave-octopi kernel: [35518.178764] usb 1-1.4: USB disconnect, device number 3
Apr 3 00:41:50 dave-octopi kernel: [35518.179210] usb 1-1.4: failed to send control message: -19
Apr 3 00:41:50 dave-octopi kernel: [35518.180969] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
Apr 3 00:41:50 dave-octopi kernel: [35518.181006] ch341 1-1.4:1.0: device disconnected
Apr 3 00:49:59 dave-octopi rngd[332]: stats: bits received from HRNG source: 360064
Apr 3 00:49:59 dave-octopi rngd[332]: stats: bits sent to kernel pool: 304096
Apr 3 00:49:59 dave-octopi rngd[332]: stats: entropy added to kernel pool: 304096
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2 successes: 18
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2 failures: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2(2001-10-10) Monobit: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2(2001-10-10) Poker: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2(2001-10-10) Runs: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2(2001-10-10) Long run: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS 140-2(2001-10-10) Continuous run: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: HRNG source speed: (min=230.915; avg=441.203; max=523.205)Kibits/s
Apr 3 00:49:59 dave-octopi rngd[332]: stats: FIPS tests speed: (min=1.993; avg=15.713; max=31.423)Mibits/s
Apr 3 00:49:59 dave-octopi rngd[332]: stats: Lowest ready-buffers level: 2
Apr 3 00:49:59 dave-octopi rngd[332]: stats: Entropy starvations: 0
Apr 3 00:49:59 dave-octopi rngd[332]: stats: Time spent starving for entropy: (min=0; avg=0.000; max=0)us
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
Octopi 0.17 running Octoprint 1.4.0, Debian Buster on a Pi4 4GB in 64 bit mode, Anet A8 running Marlin 1.1.9