/dev/ttyUSB0 file disappears on Ubuntu 22.04

/dev/ttyUSB0 file disappears on Ubuntu 22.04

[TonicLab.ru]

Hi all,

This problem appeared on a freshly installed Ubuntu 22.04 desktop. Not 
sure I need to post this here.

When I'm attaching a ftdi device into usb everything looks great but 
there's no /dev/ttyUSB0 file. Seems it created and then disappeared. I 
tried to remove brltty package (as some recommends on the net) but it 
didn't help. The same ftdi device works on older Ubuntu version w/o any 
problems.

I'm having this in syslog:
Jun  1 16:58:09 qgs-comp kernel: [  538.642086] usb 2-1.5: new 
full-speed USB device number 5 using ehci-pci
Jun  1 16:58:10 qgs-comp kernel: [  538.756437] usb 2-1.5: New USB 
device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
Jun  1 16:58:10 qgs-comp kernel: [  538.756445] usb 2-1.5: New USB 
device strings: Mfr=1, Product=2, SerialNumber=3
Jun  1 16:58:10 qgs-comp kernel: [  538.756448] usb 2-1.5: Product: USB 
Serial
Jun  1 16:58:10 qgs-comp kernel: [  538.756450] usb 2-1.5: Manufacturer: 
FTDI
Jun  1 16:58:10 qgs-comp kernel: [  538.756452] usb 2-1.5: SerialNumber: 
FT0KKBIF
Jun  1 16:58:10 qgs-comp kernel: [  538.759677] ftdi_sio 2-1.5:1.0: FTDI 
USB Serial Device converter detected
Jun  1 16:58:10 qgs-comp kernel: [  538.759713] usb 2-1.5: Detected 
FT232RL
Jun  1 16:58:10 qgs-comp kernel: [  538.760546] usb 2-1.5: FTDI USB 
Serial Device converter now attached to ttyUSB0
Jun  1 16:58:01 qgs-comp colord-sane: message repeated 2 times: [ 
io/hpmud/musb.c 2101: Invalid usb_open: Permission denied]
Jun  1 16:58:10 qgs-comp mtp-probe: checking bus 2, device 5: 
"/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
Jun  1 16:58:10 qgs-comp mtp-probe: bus: 2, device: 5 was not an MTP 
device
Jun  1 16:58:10 qgs-comp systemd-udevd[5394]: 2-1.5: Failed to 
create/update device symlink '/dev/ttyUSB0', ignoring: File exists
Jun  1 16:58:10 qgs-comp snapd[942]: hotplug.go:199: hotplug device add 
event ignored, enable experimental.hotplug
Jun  1 16:58:10 qgs-comp mtp-probe: checking bus 2, device 5: 
"/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
Jun  1 16:58:10 qgs-comp mtp-probe: bus: 2, device: 5 was not an MTP 
device
Jun  1 16:58:10 qgs-comp colord-sane: io/hpmud/musb.c 2101: Invalid 
usb_open: Permission denied

I noticed this line:

Jun  1 16:58:10 qgs-comp systemd-udevd[5394]: 2-1.5: Failed to 
create/update device symlink '/dev/ttyUSB0', ignoring: File exists

Why is it happening? There's no /dev/ttyUSB0 neither before nor after I 
attach ftdi device to a USB port.

thanks

Re: /dev/ttyUSB0 file disappears on Ubuntu 22.04

[Greg KH]

On Wed, Jun 01, 2022 at 07:37:45PM +0300, TonicLab.ru wrote:
> Hi all,
> 
> This problem appeared on a freshly installed Ubuntu 22.04 desktop. Not sure
> I need to post this here.
> 
> When I'm attaching a ftdi device into usb everything looks great but there's
> no /dev/ttyUSB0 file. Seems it created and then disappeared. I tried to
> remove brltty package (as some recommends on the net) but it didn't help.
> The same ftdi device works on older Ubuntu version w/o any problems.
> 
> I'm having this in syslog:
> Jun  1 16:58:09 qgs-comp kernel: [  538.642086] usb 2-1.5: new full-speed
> USB device number 5 using ehci-pci
> Jun  1 16:58:10 qgs-comp kernel: [  538.756437] usb 2-1.5: New USB device
> found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
> Jun  1 16:58:10 qgs-comp kernel: [  538.756445] usb 2-1.5: New USB device
> strings: Mfr=1, Product=2, SerialNumber=3
> Jun  1 16:58:10 qgs-comp kernel: [  538.756448] usb 2-1.5: Product: USB
> Serial
> Jun  1 16:58:10 qgs-comp kernel: [  538.756450] usb 2-1.5: Manufacturer:
> FTDI
> Jun  1 16:58:10 qgs-comp kernel: [  538.756452] usb 2-1.5: SerialNumber:
> FT0KKBIF
> Jun  1 16:58:10 qgs-comp kernel: [  538.759677] ftdi_sio 2-1.5:1.0: FTDI USB
> Serial Device converter detected
> Jun  1 16:58:10 qgs-comp kernel: [  538.759713] usb 2-1.5: Detected FT232RL
> Jun  1 16:58:10 qgs-comp kernel: [  538.760546] usb 2-1.5: FTDI USB Serial
> Device converter now attached to ttyUSB0

It was created here.

> Jun  1 16:58:01 qgs-comp colord-sane: message repeated 2 times: [
> io/hpmud/musb.c 2101: Invalid usb_open: Permission denied]
> Jun  1 16:58:10 qgs-comp mtp-probe: checking bus 2, device 5:
> "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
> Jun  1 16:58:10 qgs-comp mtp-probe: bus: 2, device: 5 was not an MTP device
> Jun  1 16:58:10 qgs-comp systemd-udevd[5394]: 2-1.5: Failed to create/update
> device symlink '/dev/ttyUSB0', ignoring: File exists

See it's still there.

> Jun  1 16:58:10 qgs-comp snapd[942]: hotplug.go:199: hotplug device add
> event ignored, enable experimental.hotplug
> Jun  1 16:58:10 qgs-comp mtp-probe: checking bus 2, device 5:
> "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
> Jun  1 16:58:10 qgs-comp mtp-probe: bus: 2, device: 5 was not an MTP device
> Jun  1 16:58:10 qgs-comp colord-sane: io/hpmud/musb.c 2101: Invalid
> usb_open: Permission denied

I do not see it going away.

Are you sure it is gone?  Any further log messages?

thanks,

greg k-h

Re: /dev/ttyUSB0 file disappears on Ubuntu 22.04

[Yuri]

Thanks for a quick reply, Greg. No, no error here. No matter when I 
execute this on my PC under Ubuntu 22.04

ls -l /dev/ttyUSB*

I get this

ls: cannot access '/dev/ttyUSB*': No such file or directory

I made this log after attaching and removing the device. Here's dmesg 
output

[ 2276.613198] usb 2-1.5: new full-speed USB device number 5 using 
ehci-pci
[ 2276.727502] usb 2-1.5: New USB device found, idVendor=0403, 
idProduct=6001, bcdDevice= 6.00
[ 2276.727511] usb 2-1.5: New USB device strings: Mfr=1, Product=2, 
SerialNumber=3
[ 2276.727514] usb 2-1.5: Product: USB Serial
[ 2276.727516] usb 2-1.5: Manufacturer: FTDI
[ 2276.727518] usb 2-1.5: SerialNumber: FT0KKBIF
[ 2276.729550] ftdi_sio 2-1.5:1.0: FTDI USB Serial Device converter 
detected
[ 2276.729626] usb 2-1.5: Detected FT232RL
[ 2276.730487] usb 2-1.5: FTDI USB Serial Device converter now attached 
to ttyUSB0
[ 3173.152415] usb 2-1.5: USB disconnect, device number 5
[ 3173.152974] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now 
disconnected from ttyUSB0
[ 3173.153005] ftdi_sio 2-1.5:1.0: device disconnected
[ 3182.847132] kauditd_printk_skb: 1 callbacks suppressed
[ 3396.861511] usb 2-1.5: new full-speed USB device number 6 using 
ehci-pci
[ 3396.975858] usb 2-1.5: New USB device found, idVendor=0403, 
idProduct=6001, bcdDevice= 6.00
[ 3396.975866] usb 2-1.5: New USB device strings: Mfr=1, Product=2, 
SerialNumber=3
[ 3396.975870] usb 2-1.5: Product: USB Serial
[ 3396.975872] usb 2-1.5: Manufacturer: FTDI
[ 3396.975874] usb 2-1.5: SerialNumber: FT0KKBIF
[ 3396.978651] ftdi_sio 2-1.5:1.0: FTDI USB Serial Device converter 
detected
[ 3396.978714] usb 2-1.5: Detected FT232RL
[ 3396.979568] usb 2-1.5: FTDI USB Serial Device converter now attached 
to ttyUSB0
[ 3553.309826] usb 2-1.5: USB disconnect, device number 6
[ 3553.310371] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now 
disconnected from ttyUSB0
[ 3553.310404] ftdi_sio 2-1.5:1.0: device disconnected


And here's the syslog output echoing log above

Jun  2 10:41:54 qgs-comp kernel: [ 3173.152415] usb 2-1.5: USB 
disconnect, device number 5
Jun  2 10:41:54 qgs-comp kernel: [ 3173.152974] ftdi_sio ttyUSB0: FTDI 
USB Serial Device converter now disconnected from ttyUSB0
Jun  2 10:41:54 qgs-comp kernel: [ 3173.153005] ftdi_sio 2-1.5:1.0: 
device disconnected
Jun  2 10:42:02 qgs-comp systemd[1786]: Started Application launched by 
gnome-shell.
Jun  2 10:42:03 qgs-comp libreoffice-writer.desktop[7821]: Warning: 
failed to launch javaldx - java may not function correctly
Jun  2 10:42:04 qgs-comp kernel: [ 3182.847132] kauditd_printk_skb: 1 
callbacks suppressed
Jun  2 10:42:04 qgs-comp kernel: [ 3182.847137] audit: type=1400 
audit(1654155724.011:126): apparmor="ALLOWED" operation="file_mmap" 
profile="libreoffice-soffice" name="/tmp/.glQ6PDw2" pid=7839 
comm="soffice.bin" requested_mask="m" denied_mask="m" fsuid=1000 
ouid=1000
Jun  2 10:42:04 qgs-comp kernel: [ 3183.137037] audit: type=1400 
audit(1654155724.303:127): apparmor="ALLOWED" operation="connect" 
profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" 
pid=7838 comm="soffice.bin" requested_mask="wr" denied_mask="wr" 
fsuid=1000 ouid=1000
Jun  2 10:42:04 qgs-comp kernel: [ 3183.137207] audit: type=1400 
audit(1654155724.303:128): apparmor="ALLOWED" operation="file_perm" 
profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" 
pid=7838 comm="soffice.bin" requested_mask="r" denied_mask="r" 
fsuid=1000 ouid=1000
Jun  2 10:42:04 qgs-comp kernel: [ 3183.137218] audit: type=1400 
audit(1654155724.303:129): apparmor="ALLOWED" operation="file_perm" 
profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" 
pid=7838 comm="soffice.bin" requested_mask="r" denied_mask="r" 
fsuid=1000 ouid=1000
Jun  2 10:42:14 qgs-comp systemd[1786]: 
app-gnome-libreoffice\x2dwriter-7821.scope: Consumed 3.025s CPU time.
Jun  2 10:45:38 qgs-comp kernel: [ 3396.861511] usb 2-1.5: new 
full-speed USB device number 6 using ehci-pci
Jun  2 10:45:38 qgs-comp kernel: [ 3396.975858] usb 2-1.5: New USB 
device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
Jun  2 10:45:38 qgs-comp kernel: [ 3396.975866] usb 2-1.5: New USB 
device strings: Mfr=1, Product=2, SerialNumber=3
Jun  2 10:45:38 qgs-comp kernel: [ 3396.975870] usb 2-1.5: Product: USB 
Serial
Jun  2 10:45:38 qgs-comp kernel: [ 3396.975872] usb 2-1.5: Manufacturer: 
FTDI
Jun  2 10:45:38 qgs-comp kernel: [ 3396.975874] usb 2-1.5: SerialNumber: 
FT0KKBIF
Jun  2 10:45:38 qgs-comp kernel: [ 3396.978651] ftdi_sio 2-1.5:1.0: FTDI 
USB Serial Device converter detected
Jun  2 10:45:38 qgs-comp kernel: [ 3396.978714] usb 2-1.5: Detected 
FT232RL
Jun  2 10:45:38 qgs-comp kernel: [ 3396.979568] usb 2-1.5: FTDI USB 
Serial Device converter now attached to ttyUSB0
Jun  2 10:45:38 qgs-comp mtp-probe: checking bus 2, device 6: 
"/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
Jun  2 10:45:38 qgs-comp mtp-probe: bus: 2, device: 6 was not an MTP 
device
Jun  2 10:45:38 qgs-comp systemd-udevd[7907]: 2-1.5: Failed to 
create/update device symlink '/dev/ttyUSB0', ignoring: File exists
Jun  2 10:45:38 qgs-comp snapd[938]: hotplug.go:199: hotplug device add 
event ignored, enable experimental.hotplug
Jun  2 10:45:38 qgs-comp mtp-probe: checking bus 2, device 6: 
"/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
Jun  2 10:45:38 qgs-comp mtp-probe: bus: 2, device: 6 was not an MTP 
device
Jun  2 10:45:40 qgs-comp ModemManager[1055]: <info>  [base-manager] 
couldn't check support for device 
'/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5': not supported by 
any plugin
Jun  2 10:45:47 qgs-comp kernel: [ 3406.230869] [UFW BLOCK] IN=enp5s0 
OUT= MAC=01:00:5e:00:00:01:c4:6e:1f:70:4f:f4:08:00 SRC=192.168.0.1 
DST=224.0.0.1 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2
Jun  2 10:46:34 qgs-comp systemd[1786]: Started Application launched by 
gnome-shell.
Jun  2 10:46:34 qgs-comp systemd[1786]: Started VTE child process 7940 
launched by gnome-terminal-server process 5736.
Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaWindowGroup>:0x55cea707c320] is on because it needs 
an allocation.
Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaWindowActorX11>:0x55ceb6917ed0] is on because it 
needs an allocation.
Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaSurfaceActorX11>:0x55cea8afc6c0] is on because it 
needs an allocation.
Jun  2 10:46:37 qgs-comp systemd[1786]: Started Application launched by 
gnome-shell.
Jun  2 10:46:37 qgs-comp systemd[1786]: Started VTE child process 7958 
launched by gnome-terminal-server process 5736.
Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaWindowGroup>:0x55cea707c320] is on because it needs 
an allocation.
Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaWindowActorX11>:0x55cea8e32360] is on because it 
needs an allocation.
Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views 
actor <unnamed>[<MetaSurfaceActorX11>:0x55cea8afca40] is on because it 
needs an allocation.
Jun  2 10:48:14 qgs-comp kernel: [ 3553.309826] usb 2-1.5: USB 
disconnect, device number 6
Jun  2 10:48:14 qgs-comp kernel: [ 3553.310371] ftdi_sio ttyUSB0: FTDI 
USB Serial Device converter now disconnected from ttyUSB0
Jun  2 10:48:14 qgs-comp kernel: [ 3553.310404] ftdi_sio 2-1.5:1.0: 
device disconnected


No problems on the same PC working under Ubuntu 18.04 and 16.04 
whatsoever:

ls -l /dev/ttyUSB*
crw-rw---- 1 root dialout 188, 0 Jun  2 10:36 /dev/ttyUSB0


> 
> I do not see it going away.
> 
> Are you sure it is gone?  Any further log messages?
> 
> thanks,
> 
> greg k-h

Re: /dev/ttyUSB0 file disappears on Ubuntu 22.04

[Greg KH]

On Thu, Jun 02, 2022 at 11:47:50AM +0300, Yuri wrote:
> Thanks for a quick reply, Greg. No, no error here. No matter when I execute
> this on my PC under Ubuntu 22.04
> 
> ls -l /dev/ttyUSB*
> 
> I get this
> 
> ls: cannot access '/dev/ttyUSB*': No such file or directory

Is the device node actually there?

What does /dev/serial/ contain?

> I made this log after attaching and removing the device. Here's dmesg output
> 
> [ 2276.613198] usb 2-1.5: new full-speed USB device number 5 using ehci-pci
> [ 2276.727502] usb 2-1.5: New USB device found, idVendor=0403,
> idProduct=6001, bcdDevice= 6.00
> [ 2276.727511] usb 2-1.5: New USB device strings: Mfr=1, Product=2,
> SerialNumber=3
> [ 2276.727514] usb 2-1.5: Product: USB Serial
> [ 2276.727516] usb 2-1.5: Manufacturer: FTDI
> [ 2276.727518] usb 2-1.5: SerialNumber: FT0KKBIF
> [ 2276.729550] ftdi_sio 2-1.5:1.0: FTDI USB Serial Device converter detected
> [ 2276.729626] usb 2-1.5: Detected FT232RL
> [ 2276.730487] usb 2-1.5: FTDI USB Serial Device converter now attached to
> ttyUSB0
> [ 3173.152415] usb 2-1.5: USB disconnect, device number 5
> [ 3173.152974] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now
> disconnected from ttyUSB0
> [ 3173.153005] ftdi_sio 2-1.5:1.0: device disconnected
> [ 3182.847132] kauditd_printk_skb: 1 callbacks suppressed
> [ 3396.861511] usb 2-1.5: new full-speed USB device number 6 using ehci-pci
> [ 3396.975858] usb 2-1.5: New USB device found, idVendor=0403,
> idProduct=6001, bcdDevice= 6.00
> [ 3396.975866] usb 2-1.5: New USB device strings: Mfr=1, Product=2,
> SerialNumber=3
> [ 3396.975870] usb 2-1.5: Product: USB Serial
> [ 3396.975872] usb 2-1.5: Manufacturer: FTDI
> [ 3396.975874] usb 2-1.5: SerialNumber: FT0KKBIF
> [ 3396.978651] ftdi_sio 2-1.5:1.0: FTDI USB Serial Device converter detected
> [ 3396.978714] usb 2-1.5: Detected FT232RL
> [ 3396.979568] usb 2-1.5: FTDI USB Serial Device converter now attached to
> ttyUSB0
> [ 3553.309826] usb 2-1.5: USB disconnect, device number 6
> [ 3553.310371] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now
> disconnected from ttyUSB0
> [ 3553.310404] ftdi_sio 2-1.5:1.0: device disconnected
> 
> 
> And here's the syslog output echoing log above
> 
> Jun  2 10:41:54 qgs-comp kernel: [ 3173.152415] usb 2-1.5: USB disconnect,
> device number 5
> Jun  2 10:41:54 qgs-comp kernel: [ 3173.152974] ftdi_sio ttyUSB0: FTDI USB
> Serial Device converter now disconnected from ttyUSB0
> Jun  2 10:41:54 qgs-comp kernel: [ 3173.153005] ftdi_sio 2-1.5:1.0: device
> disconnected
> Jun  2 10:42:02 qgs-comp systemd[1786]: Started Application launched by
> gnome-shell.
> Jun  2 10:42:03 qgs-comp libreoffice-writer.desktop[7821]: Warning: failed
> to launch javaldx - java may not function correctly
> Jun  2 10:42:04 qgs-comp kernel: [ 3182.847132] kauditd_printk_skb: 1
> callbacks suppressed
> Jun  2 10:42:04 qgs-comp kernel: [ 3182.847137] audit: type=1400
> audit(1654155724.011:126): apparmor="ALLOWED" operation="file_mmap"
> profile="libreoffice-soffice" name="/tmp/.glQ6PDw2" pid=7839
> comm="soffice.bin" requested_mask="m" denied_mask="m" fsuid=1000 ouid=1000
> Jun  2 10:42:04 qgs-comp kernel: [ 3183.137037] audit: type=1400
> audit(1654155724.303:127): apparmor="ALLOWED" operation="connect"
> profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" pid=7838
> comm="soffice.bin" requested_mask="wr" denied_mask="wr" fsuid=1000 ouid=1000
> Jun  2 10:42:04 qgs-comp kernel: [ 3183.137207] audit: type=1400
> audit(1654155724.303:128): apparmor="ALLOWED" operation="file_perm"
> profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" pid=7838
> comm="soffice.bin" requested_mask="r" denied_mask="r" fsuid=1000 ouid=1000
> Jun  2 10:42:04 qgs-comp kernel: [ 3183.137218] audit: type=1400
> audit(1654155724.303:129): apparmor="ALLOWED" operation="file_perm"
> profile="libreoffice-soffice" name="/run/user/1000/at-spi/bus_1" pid=7838
> comm="soffice.bin" requested_mask="r" denied_mask="r" fsuid=1000 ouid=1000
> Jun  2 10:42:14 qgs-comp systemd[1786]:
> app-gnome-libreoffice\x2dwriter-7821.scope: Consumed 3.025s CPU time.
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.861511] usb 2-1.5: new full-speed
> USB device number 6 using ehci-pci
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.975858] usb 2-1.5: New USB device
> found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.975866] usb 2-1.5: New USB device
> strings: Mfr=1, Product=2, SerialNumber=3
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.975870] usb 2-1.5: Product: USB
> Serial
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.975872] usb 2-1.5: Manufacturer:
> FTDI
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.975874] usb 2-1.5: SerialNumber:
> FT0KKBIF
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.978651] ftdi_sio 2-1.5:1.0: FTDI USB
> Serial Device converter detected
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.978714] usb 2-1.5: Detected FT232RL
> Jun  2 10:45:38 qgs-comp kernel: [ 3396.979568] usb 2-1.5: FTDI USB Serial
> Device converter now attached to ttyUSB0
> Jun  2 10:45:38 qgs-comp mtp-probe: checking bus 2, device 6:
> "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
> Jun  2 10:45:38 qgs-comp mtp-probe: bus: 2, device: 6 was not an MTP device
> Jun  2 10:45:38 qgs-comp systemd-udevd[7907]: 2-1.5: Failed to create/update
> device symlink '/dev/ttyUSB0', ignoring: File exists
> Jun  2 10:45:38 qgs-comp snapd[938]: hotplug.go:199: hotplug device add
> event ignored, enable experimental.hotplug
> Jun  2 10:45:38 qgs-comp mtp-probe: checking bus 2, device 6:
> "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5"
> Jun  2 10:45:38 qgs-comp mtp-probe: bus: 2, device: 6 was not an MTP device
> Jun  2 10:45:40 qgs-comp ModemManager[1055]: <info>  [base-manager] couldn't
> check support for device
> '/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.5': not supported by any
> plugin
> Jun  2 10:45:47 qgs-comp kernel: [ 3406.230869] [UFW BLOCK] IN=enp5s0 OUT=
> MAC=01:00:5e:00:00:01:c4:6e:1f:70:4f:f4:08:00 SRC=192.168.0.1 DST=224.0.0.1
> LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2
> Jun  2 10:46:34 qgs-comp systemd[1786]: Started Application launched by
> gnome-shell.
> Jun  2 10:46:34 qgs-comp systemd[1786]: Started VTE child process 7940
> launched by gnome-terminal-server process 5736.
> Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaWindowGroup>:0x55cea707c320] is on because it needs an
> allocation.
> Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaWindowActorX11>:0x55ceb6917ed0] is on because it needs an
> allocation.
> Jun  2 10:46:34 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaSurfaceActorX11>:0x55cea8afc6c0] is on because it needs an
> allocation.
> Jun  2 10:46:37 qgs-comp systemd[1786]: Started Application launched by
> gnome-shell.
> Jun  2 10:46:37 qgs-comp systemd[1786]: Started VTE child process 7958
> launched by gnome-terminal-server process 5736.
> Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaWindowGroup>:0x55cea707c320] is on because it needs an
> allocation.
> Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaWindowActorX11>:0x55cea8e32360] is on because it needs an
> allocation.
> Jun  2 10:46:37 qgs-comp gnome-shell[2070]: Can't update stage views actor
> <unnamed>[<MetaSurfaceActorX11>:0x55cea8afca40] is on because it needs an
> allocation.
> Jun  2 10:48:14 qgs-comp kernel: [ 3553.309826] usb 2-1.5: USB disconnect,
> device number 6
> Jun  2 10:48:14 qgs-comp kernel: [ 3553.310371] ftdi_sio ttyUSB0: FTDI USB
> Serial Device converter now disconnected from ttyUSB0
> Jun  2 10:48:14 qgs-comp kernel: [ 3553.310404] ftdi_sio 2-1.5:1.0: device
> disconnected
> 
> 
> No problems on the same PC working under Ubuntu 18.04 and 16.04 whatsoever:
> 
> ls -l /dev/ttyUSB*
> crw-rw---- 1 root dialout 188, 0 Jun  2 10:36 /dev/ttyUSB0

I think you are going to have to contact ubuntu for this issue and get
support from them as it's their kernel and overall system configuration
here, the kernel looks like it is working just fine.

good luck!

greg k-h

Re: /dev/ttyUSB0 file disappears on Ubuntu 22.04

[Yuri]

>> 
>> ls: cannot access '/dev/ttyUSB*': No such file or directory
> 
> Is the device node actually there?
> 
> What does /dev/serial/ contain?
> 

After I have a ftdi device attached I have

cd /dev/serial ; ls -LR

.:
by-id
by-path

./by-id:
ls: cannot access './by-id/usb-FTDI_USB_Serial_FT0KKBIF-if00-port0': No 
such file or directory
usb-FTDI_USB_Serial_FT0KKBIF-if00-port0

./by-path:
ls: cannot access './by-path/pci-0000:00:1d.0-usb-0:1.5:1.0-port0': No 
such file or directory
pci-0000:00:1d.0-usb-0:1.5:1.0-port0

So the folders and links are there but there's no /dev/ttyUSB0 file

>> No problems on the same PC working under Ubuntu 18.04 and 16.04 
>> whatsoever:
>> 
>> ls -l /dev/ttyUSB*
>> crw-rw---- 1 root dialout 188, 0 Jun  2 10:36 /dev/ttyUSB0
> 
> I think you are going to have to contact ubuntu for this issue and get
> support from them as it's their kernel and overall system configuration
> here, the kernel looks like it is working just fine.

Thanks for advice. Already opened a bug report on launchpad.