On Sat, Oct 19, 2013 at 03:13:35PM -0400, josh wrote: > I have a USB 802.11n capable dongle that works fine in a netbook[3] but not > in a server[2], which is where it was intended. The sypmtom is a cessation > of packet traffic followed by device timeout as described in urtwn(4). > A similar problem was mentioned last year[1] on misc@, though the specific > Realtek chipset involved was not posted. > > I built a kernel with USB_DEBUG which enables URTWN_DEBUG, and while running > with that test kernel I could not replicate the problem. From that test, I > understand that timing or a race condition are likely areas of research. It > aligns also with the slower system [3] not being able to replicate either. > > I could use some help as I am unsure how to investigate further. I tried > doubling the sc_tx_timer in if_urtwn.c from 5 to 10, with no effect, but > that was just a stab in the dark. Any suggestions for futher tests, or > a whack with a cluestick would be welcome.
I have a urtwn that runs quite hot when it exhibits similar problems. Pulling it out and letting it cool down for a while usually fixes it. Putting it back in immediately usually results in the same symptoms right away. A shot in the dark idea is that our driver might not be handling power management in a way that the vendor envisioned, so the device runs too hot and stops working properly.
