ACPI Suspend/Resume Debug Tool

UNDER DEVELOPMENT

S3 debug scripts

How to Use

0. Clone the git repo:

sudo apt-get install git
git clone git://kernel.ubuntu.com/cking/pmdebug.git

and build the locatehang tool:

cd pmdebug/locatehang
make
cd ../..

1. Install kernel debug .ddeb (this may take a while!)

1.1) Create an /etc/apt/sources.list.d/ddebs.list by running the following line at a terminal:

echo "deb http://ddebs.ubuntu.com $(lsb_release -cs) main restricted universe multiverse" |\
sudo tee -a /etc/apt/sources.list.d/ddebs.list

1.2) Import the debug symbol archive signing key:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 428D7C01

1.3) Then run:

sudo apt-get update

1.4) Download and install the debug kernel:

sudo apt-get install linux-image-$(uname -r)-dbgsym

1.5) Install systemtap

sudo apt-get install systemtap

2. Run the s3test script

cd pmdebug/systemtap
sudo ./s3test -s

There are a few optional arguments to do some deeper debugging.

        -f, --flash funcname
                flash the keyboard LEDs when we execute one of
                the s3 instrumented functions

        -b, --beep
                beep the speaker when we execute one of the
                s3 instrumented functions
        
        -r, --reboot
                reboot the machine when we execute one of the
                s3 instrumented functions

        -s      automatically suspend the machine

3. Examine the gathered data

• Full trace log in s3-systemtap.log
• Function traces in s3-trace.log (note that some inline'd functions and return paths cannot be traced).
• Device suspend/resume state in s3-devices.log
• Task suspend/resume state in s3-tasks.log
• Test results in s3-test.log

If the machine hangs, reboot the machine and run the 'locatehang' program. This will convert a hash in the Real Time Clock (RTC) back into a function hash and then lookup and determine the last instrumented function executed before the machine locked up. Note that one has to reboot the machine and run 'locatehang' fairly quickly since the RTC will overwrite the stored hash after 3 minutes.

4. Examples

sudo ./s3test -s --flash syscore_suspend

flash keyboard LEDs when we reach syscore_suspend()

sudo ./s3test -s --reboot disable_nonboot_cpus --beep usermodehelper_disable

reboot the machine if we get as far as disable_nonboot_cpus() and beep the PC speaker when we enter/exit usermodehelper_disable().