Comment 3 for bug 961202

I did a couple of tests on my setup. First of all, problem seems to disappear if i use the radeon driver instead of fglrx one. Then i ssh-ed in from another machine. This is the output of powertop with screen blank (only first few lines copied, compiz using 100% of a core):

            993,3 ms/s 0,0 Process compiz
            100,0% Device Codec audio hwC0D1: LSI
            100,0% Device Codec audio hwC0D0: IDT
              0,9 ms/s 81,6 Timer tick_sched_timer
              4,9 ms/s 15,7 Process /usr/lib/indicator-application/indicator-application-service
            108,0 µs/s 11,8 Timer hrtimer_wakeup

This the same, with screen active:

            100,0% Device Codec audio hwC0D1: LSI
            100,0% Device Codec audio hwC0D0: IDT
              3,5 ms/s 114,9 Timer tick_sched_timer
             69,7 ms/s 27,5 Process compiz
              1,6 ms/s 44,2 Interrupt [58] fglrx[0]@PCI:1:0:0
              0,9 ms/s 37,3 Interrupt [6] tasklet(softirq)
             34,8 ms/s 19,6 Process /usr/lib/unity/unity-panel-service
              9,4 ms/s 20,6 Process /usr/lib/indicator-application/indicator-application-service
              9,0 ms/s 20,6 Process //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session
            620,4 µs/s 16,7 Timer hrtimer_wakeup

fglrx interrupts are absent in the first lot. Is this expected?