Comment 3 for bug 39815

I tried to connect the cdrom to a different computer to get the info but it worked there. I also had a problem with a Sony cdrom connected to an i440BX mainboard. The system would lock up when trying to read the cd, and it required me to wait for a while, press a key(!), and then the kernel woud reset the interface and disable dma. It also worked when I tried to connect the drive to a different board.

So I would suggest disabling cdrom dma on i4x0 chipsets by default. It works sometimes but not always.