Comment # 12 on bug 964621 from Takashi Iwai

Also, try to enable tracing and gather verbs while suspend/resume.
    # echo 1 > /sys/kernel/debug/tracing/events/hda/enable

    ... do suspend and resume...

    # cat /sys/kernel/debug/tracing/trace > trace.log

    # echo 0 > /sys/kernel/debug/tracing/events/hda/enable