Slow Ethernet throughput and framing errors when connected via a hub
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-fsl-imx51 (Ubuntu) |
Fix Released
|
Medium
|
Bryan Wu |
Bug Description
Ubuntu lucid
linux-fsl-imx51 2.6.31.603.4 (and other versions)
Observed on Babbage 2.0 and Babbage 3.0
When connected to the network via a hub, TCP throughput will commonly drop down to ~100-200 kB/s, and NFS becomes sticky / unreliable, significantly impairing board usability.
When connected directly to a switch, full throughput is observed (~2-4 MB/s in our case)
This does not happen on Karmic (Babbage 2.0) or Jaunty (Babbage 1), and did not initially happen with lucid. The problem appeared to start when the 2.6.31 fsl kernel was merged (but I have no evidence for this now).
For now I'm assuming that this is an armel-specific issue, but since hubs are not in common use for most people, it could be more widespread.
Why kind of hub was this tested with? Has this been tested with more than one model of hub, or is it possible that it could be related to just that particular device?