when I try to edit the latency_timer of /dev/ttyUSB0 on my laptop I get an error.
Here what I do:
$ sudo vim /sys/bus/usb-serial/devices/ttyUSB0/latency_timer
When editing 16 to 1 and saving, I got in vim this error:
"/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0/ttyUSB0/latency_timer" E514: write error (file
system full?)
WARNING: Original file may be lost or damaged
don't quit the editor until the file is successfully written!
Unfortunately I am not expert enough to know what I should do.
I get that I should check that the filesystem partition /sys is full or not; indeed looking on internet it seems that I have to use command df.
Here the output of df coomand:
$ sudo df -h
Filesystem Size Used Avail Use% Mounted on
udev 7,7G 0 7,7G 0% /dev
tmpfs 1,6G 2,1M 1,6G 1% /run
/dev/nvme0n1p7 192G 119G 63G 66% /
tmpfs 7,7G 231M 7,5G 3% /dev/shm
tmpfs 5,0M 4,0K 5,0M 1% /run/lock
tmpfs 7,7G 0 7,7G 0% /sys/fs/cgroup
/dev/loop1 15M 15M 0 100% /snap/gnome-characters/359
/dev/loop2 135M 135M 0 100% /snap/mathpix-snipping-tool/39
/dev/loop3 256K 256K 0 100% /snap/gtk2-common-themes/5
/dev/loop4 3,8M 3,8M 0 100% /snap/gnome-system-monitor/111
/dev/loop5 8,2M 8,2M 0 100% /snap/evince/224
/dev/loop6 8,2M 8,2M 0 100% /snap/evince/214
/dev/loop7 3,8M 3,8M 0 100% /snap/gnome-system-monitor/107
/dev/nvme0n1p1 676M 91M 586M 14% /boot/efi
/dev/loop9 203M 203M 0 100% /snap/vlc/1049
/dev/loop8 141M 141M 0 100% /snap/gnome-3-26-1604/98
/dev/loop0 20M 20M 0 100% /snap/okular/63
/dev/loop12 261M 261M 0 100% /snap/kde-frameworks-5-core18/32
/dev/loop10 157M 157M 0 100% /snap/gnome-3-28-1804/91
/dev/loop13 90M 90M 0 100% /snap/core/8039
/dev/loop16 256M 256M 0 100% /snap/kde-frameworks-5-core18/30
/dev/loop14 1,0M 1,0M 0 100% /snap/gnome-logs/73
/dev/loop15 43M 43M 0 100% /snap/gtk-common-themes/1313
/dev/loop17 15M 15M 0 100% /snap/gnome-characters/367
/dev/loop19 175M 175M 0 100% /snap/inkscape/5874
/dev/loop18 1,0M 1,0M 0 100% /snap/gnome-logs/81
/dev/loop20 135M 135M 0 100% /snap/mathpix-snipping-tool/40
/dev/loop21 410M 410M 0 100% /snap/gimp/227
/dev/loop23 55M 55M 0 100% /snap/core18/1265
/dev/loop24 4,3M 4,3M 0 100% /snap/gnome-calculator/536
/dev/loop25 45M 45M 0 100% /snap/gtk-common-themes/1353
/dev/loop26 220M 220M 0 100% /snap/gimp/189
/dev/loop28 4,3M 4,3M 0 100% /snap/gnome-calculator/544
/dev/loop27 141M 141M 0 100% /snap/gnome-3-26-1604/97
/dev/loop29 157M 157M 0 100% /snap/gnome-3-28-1804/110
tmpfs 1,6G 84K 1,6G 1% /run/user/1000
/dev/loop30 55M 55M 0 100% /snap/core18/1279
/dev/loop31 90M 90M 0 100% /snap/core/8213
However looking at the output of this command I am not able to spot the problem or to understand if partition /sys is full.
I have tried also to remove all temporary files and to empty the trash bin, but it did not solve the problem.
Does somebody of you have any idea of what can cause the error I got and how to solve it?
Any help is really appreciated :)
You are not supposed to edit these files using vi, just write values using echo. Vim will try to create a file in the same directory and rename it over the latency_timer file which does not work in /sys
Instead, use something like:
echo 1 > /sys/bus/usb-serial/devices/ttyUSB0/latency_timer
If you must run this as a regular user, use sudo tee:
echo 1 | sudo tee /sys/bus/usb-serial/devices/ttyUSB0/latency_timer > /dev/null