Daily Archives: January 23, 2013

Garmin ANT USB Stick/Agent Issues

Virtually every triathlete I know owns a Garmin product of some kind and I’m no exception. I’ve been using Garmin hardware products for over 5 years now and am continually disappointed with several aspects of the experience. Here’s my latest issue. It’s probably not a big deal but if you have a Garmin USB stick plugged into your Mac and are running the Garmin ANT agent, you might want to check this out.

The Problem

I have a Mac Pro tower that I run as a server. It’s always on. I decided I would plug my Garmin USB stick into it and leave the agent software running. That way, whenever I came home, I would put my Garmin (310XT) on the computer table while I went to shower and my workout data would be downloaded and ready to go. This has been working well for about 6 months. This morning, completely unrelated, I was perusing my system log (via the Console app) and noticed a LOT of activity I had never seen before. There were literally hundreds of lines that said:

Jan 23 08:12:30 Mac-Pro kernel[0]: USBF: 3091688.364 AppleUSBUHCI[0xffffff80e1014000]::Found a transaction past the completion deadline on bus 0x3d, timing out! (Addr: 2, EP: 1)

I don’t know all the details behind what’s going on here but it appears if the Garmin USB stick is plugged in and the Garmin ANT Agent software is running, it polls the USB bus every 1-2 seconds. During this “activity” it seems the agent software does not quite clean up after itself, causing lots of system log entries. Surprise, surprise.

Now, this is probably not a big deal for my dual processor, quad core Mac Pro. However, I imagine there has to be some sort of performance hit, not to mention severely bloated log files (which make finding something you are really looking for quite difficult).

The Solution

Fortunately, there’s an easy fix. Just unplug your stick and the agent software stops polling. No idea if this affects Windows users and realistically, I doubt it affects many people but I thought I’d share.

Update Feb 2, 2013: I’m actually doing the reverse now. I leave the stick plugged in and just run the ANT Agent app when I want to download data.