No ACPI support for my PC, what can I do?

On my new PC something is wrong with ACPI support under Linux. I have to boot it with acpi=off and nolapic. Also it detects only one CPU core (this annoys me the most) and won't shut down completely, I have to hold power button for few seconds to power PC off.

The question is: what can I do? Edit some config files? Report bugs? Send mails to motherboard manufacturer? Run some utility to help reverse-engineer drivers? (Currently I just turn AMD C1E off in BIOS. It's a nice workaround.)

My configuration:

• Ubuntu 12.04 (upgraded from 11.10)
• Processor AMD FX(tm)-4100 Quad-Core
• RAM 8,00 GB
• Graphic Gigabyte GV-N56GOC-1GI (NVIDIA GeForce GTX 560)
• Mainboard Gigabyte GA-870A-USB3
• Disk ATA OCZ-AGILITY3 (SSD)

I suggest you start by trying to follow the steps in this guide: DebuggingACPI.

The description at the top of that page says it is part of Debugging Central, "pages with debugging details for a variety of Ubuntu packages" on the Ubuntu Community Wiki.

You should also try looking at the entries in /var/log/syslog to see if anything there will help isolate the problem.

Make sure the portion of the log you look at is from a failed boot. That is, the log entries should be from a boot where neither acpi=off nor nolapic were used. The log timestamps should allow you to determine which boot a log file entry is from.

If you find it easier to use a GUI application, Ubuntu has a Log File Viewer which you can use. It can be found by searching for it using Dash.

The steps below are (pretty much) copied from the DebuggingACPI page and are what I suggest you do to try to isolate the problem before filing a bug report. (I believe the procedures for reporting a bug are also on the DebuggingACPI page)

If acpi=off allows the system to boot, try to isolate the ACPI issue with the following boot parameters. Remove acpi=off and boot with only one of the options below.

If you are lucky, you might find a combination of kernel parameters which allows you to boot and use all the cores of your CPU.

Note: If you need an explanation of to how to do a "one time" change of the kernel boot parameters/options, try this answer to the question "How do I add a kernel boot parameter?".

• Try booting with acpi=ht
  This disables all of ACPI except just enough to enable Hyper Threading.
  
  If acpi=off works and acpi=ht fails, then the issue is in the ACPI table parsing code itself, or perhaps the SMP code.
• Try booting with pci=noacpi
  This disables ACPI for IRQ routing and PCI scanning.
• Try booting with acpi=noirq
  This disables ACPI for IRQ routing.
• Try booting with pnpacpi=off
  This disables the ACPI component of the Linux Plug and Play code.
• Try booting with noapic
  Disables the IO-APIC for IRQ routing or PCI scanning.
• Try booting with nolapic
  Disables the local APIC.

There is a better workaround than disabling ACPI (by using acpi=off and nolapic). You can just turn AMD C1E off in BIOS!

It still is an issue though...