Power Management is on when on battery.
I was looking at the powertop output at these times. I found some useless drivers loaded which had to be blacklisted. I followed this doc. http://wiki.debian.org/KernelModuleBlacklisting
Must be noted that some modules when blacklisted may not take effect and can be loaded back. ldd command can help to find its dependant modules and in which case they need to be blacklisted as well. But that has not helped here.
Here is the iwconfig output as asked for.
@mintbox ~ $ iwconfig
wlan0 IEEE 802.11bgn ESSID:"phoenix"
Mode:Managed Frequency:2.412 GHz Access Point: E8:40:F2:1D:5E:73
Bit Rate=65 Mb/s Tx-Power=14 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Link Quality=65/70 Signal level=-45 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:4 Invalid misc:168 Missed beacon:0
lo no wireless extensions.
@mintbox ~ $
The tunables option in powertop has toggle control to change values but the changes don't take effect after a reboot. Can anyone tell me how to make it permanent?