I've been reading the two Ubuntu threads about this in more detail, plus the umpteen blog posts and other forum posts that are scattered across the Web about this issue. It's actually quite interesting because it highlights how poor ACPI support in BIOSs and some Linux kernels can be. For example, I happened to notice one person commenting that if they turned ACPI off their DVD drive started to work!:
But brings up another point, I set up a Lenovo laptop for a lady, but there is obviously a BIOS issue. One of two things happen, either it ignores the CD/DVD hardware or It won't suspend resume.
The two are mutually exculsive. I can enable ACPI, and I get suspend resume, but the OS in unable to see the CD/DVD harware, it's as if it doesn't exist. Or I can turn ACPI off, I get no suspend resume, and in fact I get no auto poweroff either, but the OS can see the CD /DVD hardware, and it mounts a CD or DVD fine. This has got to Faulty BIOS. The question this article raises for me is "is this deliberate?"
Now, I expect the optical drive in the lady's Lenovo laptop is ATA, ATAPI or whatever. But that's not always the case. For example the internal optical drive on my Acer laptop appears to be USB-connected (diagnostics under Linux and Windows XP report it as a USB drive, and it runs slower than I would expect for an ATA or ATAPI device), so the following text from another Web site entitled "Various notes about Acer Travelmate 3004WTMi with Linux" (different model to mine) is also interesting:
Boot with “pci=noacpi” or even “acpi=off”. You won’t have ACPI power saving, but the external Firewire DVD-drive and network will work. On at least installed system, “linux pci=noacpi” seems to be enough.
This Foxconn story has highlighted ACPI support in firmware/software. Even if the guy who first raised this issue, one "Ryan", is wrong about Foxconn deliberately sabotaging a BIOS against Linux, it looks like there might now be some much-needed focus on improving ACPI support for Linux in some BIOSes and some Linux kernels. The SL Forum, and many other Linux distros' forums, have numerous threads relating to ACPI problems. So perhaps this guy has done Linux a favour, even if some of his language comes across as rather obnoxious.