Kernel Bug Tracker – Bug 15811
ark3116 changes minor if open across suspend
Last modified: 2013-04-09 06:23:26 UTC
My USB serial dongle is driven by ark3116. After plugging it in, it's assigned to node /dev/ttyUSB0. However, if it's opened by some process when I suspend the machine, after resume it appears as /dev/ttyUSB1. It changes back and forth between ttyUSB0 and ttyUSB1 if it's opened at suspend time (and the connection is broken each time, of course). It keeps its minor if it isn't opened at suspend time. Otherwise the device works well with both minors. The issue is reproducible by
echo devices >pm_test
echo mem >state </dev/ttyUSB0
It's great that kernel bugzilla is back.
can you please verify if the problem still exists in the latest upstream
Yes, the issue is present under 3.2. However, now I think it basically comes down to missing suspend/resume support in the ark3116 driver: the USB core has no choice besides unbinding the driver for the suspend period. If so, this is more a feature request than a bug report...
re-assign to the USB experts.