[Bug 836250] Re: [Oneiric] [Regression] Intel Corporation Centrino Ultimate-N 6300 poor networking, packet loss and very slow Lenovo X201 and T500 laptops

[Mathieu Trudel-Lapierre]

I'm at a loss as to how to debug this at the NetworkManager level.
Nothing is truly special there; what we do is basically just detect the
type of device to know whether to pass ap_scan=1 or ap_scan=2 to
wpasupplicant, which is what actually establishes and keeps the
connection up. Other code looks at stats for speed, range, etc.
calculation, but that's hardly something that would affect speed. Then
there's the obvious background scanning, but this isn't causing any
issue on other cards.

As a test, could you please try to run Precise with the latest
NetworkManager from the NetworkManager trunk ppa (http://launchpad.net
/~network-manager/+archive/trunk). There's been some changes to the wifi
code in git, so it's worth verifying.

As for another test; please try to run just wpasupplicant from Oneiric
on Natty, and see if this causes the connection to not get the expected
performance.

>From there, we'll need full syslog of what happens while testing the connection performance, preferably with NetworkManager in debug: you can get this easily after starting NetworkManager but using the debug helper script here:
http://cgit.freedesktop.org/NetworkManager/NetworkManager/plain/test/debug-helper.py

Call it as   "debug-helper.py --nm debug"; we want to get all the
debugging information available.

If nothing helps, packet captures when experiencing the problem would
certainly shed more light on what's happening.

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Title:
  [Oneiric] [Regression] Intel Corporation Centrino Ultimate-N 6300 poor
  networking, packet loss and very slow Lenovo X201 and T500 laptops

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