Little tweak here and there

I am unfortunate that I own a hard disk (Hitachi HTS722012K9SA00) that had a too aggressive power management. See https://bugs.launchpad.net/ubuntu/+source/acpi-support/+bug/59695 for details.

I tried different settings of "hdparm -B" and have observed the following:

127 - spins down and parks the head
128 to 191 - parks the head
192 to 255 - never parks the head

I have also observed that when the 6910p is on battery it does not keep on unparking the head. It seems that the best settings in battery is the default 128. I am now using 128 as the apm value when on battery. I have also added a script "/etc/acpi/resume.d/99-fix-hd.sh" as it seems "/etc/acpi/power.sh" will set never call "hdparm -B" as the power has never changed state when the laptop resumes. My 99-fix-hd.sh contains the following:

#!/bin/sh

. /etc/default/acpi-support
. /usr/share/acpi-support/power-funcs

for x in /proc/acpi/ac_adapter/*; do
    grep -q off-line $x/state

    if [ $? = 0 ] && [ x$1 != xstop ]; then     
        if [ x$ENABLE_LAPTOP_MODE = xtrue ]; then
            $HDPARM -S $SPINDOWN_TIME /dev/sda 2>/dev/null
            $HDPARM -B 128 /dev/sda 2>/dev/null
        fi
    else
        if [ x$ENABLE_LAPTOP_MODE = xtrue ]; then
            $HDPARM -S 0 /dev/sda 2>/dev/null
            $HDPARM -B 254 /dev/sda 2>/dev/null
        fi
    fi
done

For the past 2 days my 6910p wireless seems to be disconnecting. I am not sure if my wireless is getting interference from another AP or not, as this has happened to my other laptops before. I haven't seen this problem from the 6910p for a few weeks or my old nx8220. I have also changed my WRT54G firmware from thibor to tomato firmware for the past few days. Maybe the tomato firmware is causing the problem, but I doubt it so I decided to upgrade my iwlwifi from 1.2.22 to 1.2.23 and mac80211 from 10.0.2 to 10.0.4. So far it looks alright after several hours of use. I have to wait a few more hours, as it it happened for the past few days near midnight... maybe there is something happening to the 2.4ghz rf during that time in our neighborhood.

I am also trying to look at my power draw with the help of powertop from intel. Not sure how much I can save with the tweaks... still playing with it.