Comment 23 for bug 896582

This bug affects me too, on a Lenovo S205 running Oneiric 64-bit with the latest 3.0.0.13 kernel.

The laptop uses an RT3090 WLAN chipset and is serviced by the rt2800pci kernel module/driver.

I too see VERY poor speeds (downstream of well under 1Mbps) "out of the box" unless I workaround the issue. After weeks of tests I have found one such fix:

My workaround (after blacklisting acer_wmi to get the WLAN up in the first place - see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/875659) is to run with the latest kernel (at least 3.0.0.13 - this does NOT work with earlier versions) plus also use the rt2x00 drivers from compat-wireless from 22nd November 2011. This daily version (plus the ones from a few days before) included a patch to rt2800pci.c which appears to solve the situation. See the patch here: https://git.kernel.org/?p=linux/kernel/git/linville/wireless.git;a=commit;h=4ba7d9997869d25bd223dea7536fc1ce9fab3b3b

There was a bug raised on the Redhat bugzilla about this too:
https://bugzilla.redhat.com/show_bug.cgi?id=658451

HOWEVER: this particular patch to the wireless branch of git was *reverted* after 22/11/11 since the owner did not think the patch was correct despite it actually fixing this speed issue (at least on my hardware)! See here: https://git.kernel.org/?p=linux/kernel/git/linville/wireless.git;a=commit;h=82e5fc2a34fa9ffea38f00c4066b7e600a0ca5e6

What has also helped for me is adding to /etc/rc.local:

iwconfig wlan0 power off

Now I have acceptible working wireless under Oneiric 64-bit on this Lenovo S205 machine but ONLY after the above workaround.

It certainly appears to be an issue with the kernel modules (or more specifically the rt2x00 drivers included with the Ubuntu-packaged kernel).