[intrepid] fix for suspend / resume on HP TC1100

[Bartek]

Outlined below are steps to get suspend / resume functionality fully working on intrepid on a HP TC1100 tablet. Incredibly, it suspends and resumes in less than 3 seconds each way making it highly usable. (Big Kudos to pm-utils developers!)

My version of the TC1100 came with an atheros wireless card. However, the ath_pci driver does not seem to survive a suspend without being explicitly listed.

If it is not listed, when waking up the card appears to be working fine but, even after hundreds of tries, I cannot log into the network (WPA-PSK here), it keeps asking me for the password. Unloading and reloading the ath_pci module and manually doing step (3) fixes it.

This is how I got it working automatically

1) module tc1100-wmi MUST be loaded, it provides controls for turning wireless on and off
2) create /etc/pm/config.d/config with SUSPEND_MODULES="ath_pci"
3) create a script in /etc/pm/sleep.d/ to turn off wireless and turn on wireless again using the tc1100-wmi interface (see 35wireless attachment)

Find attached lspci, lsusb and aforementioned script

Known issues:
tc1100-wmi cannot be used to probe the state of the wireless card, cat /sys/devices/platform/tc1100-wmi/wireless ALWAYS reports 0 whether wireless is off or on. This means that if wireless was off when suspending, it will wake up with wireless turned on.