6 ACPI

You are reading this section, because you want all your devices to run correctly (for example, the sound card, memory stick, modem), or you want to expirement with ACPI support in Linux. It should be noted that ACPI support under Linux is experimental, and not all the features are fully supported.

The reason the modem, sound, or additional hardware may not have worked properly is because of IRQ conflicting. ACPI fixes this, as it provides correct IRQ routing. Therefore, the hardware will work fine.

This will require compiling the kernel from scratch. You will need the latest kernel, and the latest ACPI patch, which will be compiled into the kernel. You may download the patches from the ACPI Linux homepage.

After unpacking the kernel, you will need to patch it with the ACPI patch above:

# gunzip acpi-xxx.diff.gz
# cd /path/to/linux-source
# patch -p1 < /path/to/acpi-xxx.diff

Then you may compile the kernel as you normally do. If the patch complains in any way, you probably don't have the correct patch made for a specific kernel.

If everything patched finally, you can compile the kernel normally. You will just have to go under the General Setup, and choose the ACPI Support. You will be presented with other options. You should say Yes to ACPI Support, and any of the other additional choices you may want (for example, AC Adapter, Battery, Button, and so on).

After compiling, and after rebooting, you should see the following messages with dmesg:

ACPI: Interpreter enabled
ACPI: Using PIC for interrupt routing
....

After bootup, it's interesting to note that if you view your IRQ settings, everything still routes to IRQ 9, but things work fine after the patching. My settings looked just like they did before the patch was applied, though this time, everything worked smoothly. From /proc/interrupts:

9:      30046          XT-PIC  acpi, usb-uhci, usb-uhci, usb-uhci, Intel ICH3, e100