Sorry for the late answer. I also tested with Leann's kernels (thanks for providing them!) and got different (but not too bad) results:
Ubuntu kernel 3.0.0-12.19
* HDMI1 enabled: 1400 ms
* HDMI1 ignored: 800 ms
Ubuntu kernel 3.0.0-12.20~fdo41059cmt14 + bit_test=1
* HDMI1 enabled: 150 ms
* HDMI1 ignored: 150 ms
Ubuntu kernel 3.0.0-12.20~fdo41059cmt15
* HDMI1 enabled: 150 ms
* HDMI1 ignored: 150 ms
So both cases are equally better than the original one (I have no idea why those numbers changed so much from Ubuntu's kernel 3.0.0-12.18 to 3.0.0-12.19).
Sorry for the late answer. I also tested with Leann's kernels (thanks for providing them!) and got different (but not too bad) results:
Ubuntu kernel 3.0.0-12.19
* HDMI1 enabled: 1400 ms
* HDMI1 ignored: 800 ms
Ubuntu kernel 3.0.0-12. 20~fdo41059cmt1 4 + bit_test=1
* HDMI1 enabled: 150 ms
* HDMI1 ignored: 150 ms
Ubuntu kernel 3.0.0-12. 20~fdo41059cmt1 5
* HDMI1 enabled: 150 ms
* HDMI1 ignored: 150 ms
So both cases are equally better than the original one (I have no idea why those numbers changed so much from Ubuntu's kernel 3.0.0-12.18 to 3.0.0-12.19).