Comment 0 for bug 597070

I tried to install Lucid on the new Apple Imac27" with ATI radeon HD 4850 video card. After selected "install", the screen goes black. few investigations later, I discovered display output switch to the Mini Display Port. So, I treid to connect a second screen, and I was right : just after select "install lucid", the video outuput switch to the second screen, and the main screen turn black.

I continue my installation using my 2nd screen (connected to the mini display port), and after it, I'm on the desktop. I activate Open radeon drivers, the works perfectly, but in the second screen. Impossible to switch to the main screen. It's not reconized, and stay black.

I tried proprietary ati drivers (10.6). With them, I can activate my main screen, but they are not better than the open ones : there is a big vsync bug. Actually, It's totally impossible for a normal user to use open ati drievrs on the main screen with an Imac27 and ati radeon 4850 graphik card.

I think issue is in the kms driver, I tried to desactivate them. Main screen is reconized, but impossible to turn it on, it stay black, and Vsync issue re-appear on the second screen.

i tried 2.6.32, 2.6.34, 2.6.35 rc1 released, bug is still here.