Serial port not detected

xsysel

New Member
Jan 2, 2023
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Hello all,
I would like to ask you for support as I am lost now..

I installed proxmox 7.3 on my machine and transferred data from old proxmox machine running for years. I have OneWire adapter connected to physical COM port on new machine and pass-through into LXC. It was working, but after restart of proxmox it stopped and I am not able to get it running anyway.

To give you history what I did and what is in syslog..
Installed proxmox and running it for first time, I can see in syslog two serial ports detected (without adapter connected):
Code:
Dec  1 19:47:49 suchdol kernel: [    0.284303] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec  1 19:47:49 suchdol kernel: [    0.304795] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
Dec  1 19:47:49 suchdol kernel: [    0.325694] 00:06: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A

after that multiple restarts done this is seen in syslog (no ttyS0 and ttyS1 information)
Code:
Dec  1 20:52:35 Suchdol kernel: [    0.284487] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec  4 12:37:33 Suchdol kernel: [    0.284093] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec  4 20:23:37 Suchdol kernel: [    0.284249] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec 11 12:31:37 Suchdol kernel: [    0.284780] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec 15 13:13:10 Suchdol kernel: [    0.284628] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec 16 15:48:50 Suchdol kernel: [    0.284646] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled

then additional restart and ttyS0 and ttyS1 detected
Code:
Dec 22 19:14:42 Suchdol kernel: [    0.284587] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Dec 22 19:14:42 Suchdol kernel: [    0.305080] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
Dec 22 19:14:42 Suchdol kernel: [    0.325970] 00:06: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A

I connected adapter after that, set pass-through to LXC, setup everything, tested reading sensors, all worked fine. I installed setserial here.
After that I can see different output in syslog (setserial) and serial port stopped working - /dev/ttyS0 is visible, but not accessible in LXC
Code:
Jan  1 15:22:36 Suchdol kernel: [    0.284449] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled
Jan  1 15:22:36 Suchdol setserial[917]: /dev/ttyS0 at 0x03f8 (irq = 4) is a 16550A
Jan  1 15:22:36 Suchdol setserial[919]: /dev/ttyS1 at 0x02f8 (irq = 3) is a 16550A
Jan  1 16:24:25 Suchdol setserial[47988]: /dev/ttyS0 at 0x03f8 (irq = 4) is a 16550A
Jan  1 16:24:25 Suchdol setserial[47990]: /dev/ttyS1 at 0x02f8 (irq = 3) is a 16550A

I tried to setserial to kernel, remove setserial completely, but nothing help..
Without setserial installed I can see only this:
Code:
Jan  1 20:22:13 Suchdol kernel: [    0.284351] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled

Did I messed something completly with setserial? Can this be hardware issue as it was not shown every boot on the beginning?
I found similar behaviour here https://unix.stackexchange.com/questions/360193/serial-port-only-recognized-with-acpi-off-boot-flag and tried acpi=noirq without success..

Thank you very much for your help and suggestions..
 
I solved that, in case anyone would be experiencing same issue...
In my case it helped to disable Fastboot option in BIOS. Due to some reason if this option is enabled Serial port is detected only during standard power off/power on boot. During reboot it is not detected,,

I hope it will help..
 
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