Red Hat Bugzilla – Bug 824028
repeated hot plug of usb gps assigns incremental numbers
Last modified: 2012-05-22 12:04:05 EDT
Description of problem:
I plug usb gps into fc17 with all updates - previously
always assigned /dev/ttyUSB0 now I get /dev/ttyUSB1 ,2
Version-Release number of selected component (if applicable):
disconnect usb gps then reconnect - check /var/logs/messages
to see the device being assigned.
Steps to Reproduce:
alway assign /dev/ttyUSB0 to the gps at connect time
it seems this change occurred very recently but not sure exactly when
it happened as the first connection does assign /dev/ttyUSB0
and gps applications will work. After that though unplugging
the gps and then plugging it back in get the wrong device id.
/dev/ttyUSB1 and so on.
ok further testing today and navit is working so
I give up there is definitely something odd
but I cannot figure it out at the moment.
That's all expected behavior. Kernel names are not predictable. On disconnect
while the device is till in use the kernel device is busy, the reconnect will
get the next free number, all usual and expected behaviour.
You might want to use the /dev/serial/by-* links instead of the kernel names,
they are predictable.