Description:
When a gps dongle is hotplugged gpsd is not autostarted. If gpsd is already running and accepting commands on the correct socket, gpsd is notified devices that have been added. However gpsd does not receive "device removed" notifications.

Problem #1
In "/etc/udev/rules.d/99-gpsd-usb.rules" the two udev rules for the first device are commented out and disabled. I don't see any reason for this. "Bus 004 Device 010: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port" is a common usb<->serial interface used by many - mainly SiRF - gps products. Since all gps usb dongles use usb<->serial interfaces that could possibly be found in non-gps products, rules should not be commented out on the off chance of triggering false-negatives.

Problem #2
Once the udev rules are fixed, the "/etc/hotplug/usb/gpsd" script is triggered. However, this fails to autostart gpsd if it is not already running, and furthermore fails to notify gpsd of removed devices.
- Calling "/etc/hotplug/usb/gpsd" from bash works as expected. Running "sudo /etc/hotplug/usb/gpsd add /dev/ttyUSB0" will start gpsd if not running and notify gpsd of a new device. Running "sudo /etc/hotplug/usb/gpsd remove /dev/ttyUSB0" will tell gpsd to remove the device from the list. Therefore if the "/etc/hotplug/usb/gpsd" script is in error (I doubt it) the problem must lie with the hotplug(action, devpath) function.

I assume udev succesfully calls "/etc/hotplug/usb/gpsd" because gpsd logs
- gpsd: <= control(6): adding /dev/ttyUSB0
- gpsd: stashing device /dev/ttyUSB0 at slot 0
When the dongle has been hotplugged.

However, I can't ascertain that the script is also called on "remove" events. "udevadm monitor --property" records four kernel and four udev events for each connect/disconnect of the gps device. On either remove/add one event is in the tty subsystem, so the script *should* be triggered, but neither dmesg or udevadm list futher details.

So, summary: I don't know why notification doesn't always work, or how to find out, but I would be happy to help.


Additional info:
* package version(s)
community/gpsd 2.92-1