Comment 25 for bug 36185

(In reply to comment #23)
> Obviously, this needs some serious thought put into it to develop a proper
> solution as there are thousands of different types of CDROM out there. For the
> time being, it would be nice if the new Ubuntu release set DMA on some of the
> most popular types of CDROM drive out there. You have the Ubuntu hardware
> database now, what are the top ten CDROM drives out there?
>
> For reference, my CDROM is a "TOSHIBA CD/DVDW SD-R5372" and DMA works on there.
> My work machine is a "HL-DT-ST RW/DVD GCC-4481B" and DMA works on there as well.

It isn't at all clear that it is safe to enable DMA on a drive simply because it
is popular. In fact, as mentioned earlier in this bug, it isn't clear that the
drive is the only variable. In the past, we've seen different behaviour with
the same drive in two different systems.

We don't have enough information to make an educated guess yet, and given that
the consequence of disabling it by default is that CD-ROM access is slow, while
enabling it in some configurations results in the system locking up, we have
little choice but to choose the safe route for now.