[kwlug-disc] USB tty driver 'stuck'

[Khalid Baheyeldin]

So here is the situation.
I have a few serial devices and they behave well.
Each gets the device /dev/ttyUSB0 device when plugged.
They use the cp210x driver.

No issues for years.

Until today.
Somehow a wrong a sequence, maybe unplugging while a program is still
accessing the device,
made every device that gets plugged in get /dev/ttyUSB1 instead of 0.

No matter what I do, it stays 1. I tried the following:

sudo udevadm control --reload
sudo service udev restart
sudo rmmod cp210x
rmmod: ERROR: Module cp210x is in use
But nothing is plugged in.

Trying to force it does not work either:

sudo rmmod -f cp210x
rmmod: ERROR: ../libkmod/libkmod-module.c:799 kmod_module_remove_module()
could not remove 'cp210x': Resource temporarily unavailable
rmmod: ERROR: could not remove module cp210x: Resource temporarily
unavailable

I know a reboot will fix it, but I don't want to keep rebooting if this
happens again.

Any other ideas?

-- 
Khalid M. Baheyeldin
2bits.com, Inc.
Fast Reliable Drupal
Drupal performance optimization, hosting and consulting.
"Sooner or later, this combustible mixture of ignorance and power is going
to blow up in our faces." -- Dr. Carl Sagan
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