5. DSDT: Differentiated System Description Table

Thanks to Erich writing this section.

You might need to override the DSDT when certain features like battery status are incorrectly reported (usually causing error messages to syslog). DELL laptops usually need this kind of override. Fixed DSDT for many systems are available on the DSDT page, along with a patch that tells the kernel to ignore the BIOS-supplied table but use the compiled-in fixed DSDT.

Basically you need to copy the fixed table into your kernel source with a special filename (or modifing the filename in the patch supplied at the DSDT page) This override is quite easy: instead of loading the DSDT table from bios, the kernel uses the compiled-in DSDT table. That's all.