Bug 824028

Summary:	repeated hot plug of usb gps assigns incremental numbers
Product:	[Fedora] Fedora	Reporter:	Patrick Stanistreet <pystanis>
Component:	udev	Assignee:	udev-maint
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	17	CC:	harald, jonathan, udev-maint
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-05-22 15:51:10 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Patrick Stanistreet 2012-05-22 15:27:49 UTC

Description of problem:
I plug usb gps into fc17 with all updates - previously
always assigned  /dev/ttyUSB0   now I get /dev/ttyUSB1 ,2
etc.  

Version-Release number of selected component (if applicable):


How reproducible:
disconnect usb gps then reconnect - check /var/logs/messages
to see the device being assigned.

Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:
alway assign  /dev/ttyUSB0  to the gps at connect time

Additional info:

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.

Comment 1 Patrick Stanistreet 2012-05-22 15:51:10 UTC

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.

Comment 2 Kay Sievers 2012-05-22 16:04:05 UTC

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.