Am Dienstag, den 08.07.2008, 09:31 +0800 schrieb Zhao Yakui: > The C-state mapping between CPU C3/C4/C5/C6 and ACPI C3 is defined > in ACPI tables, which is related with the BIOS. In order to use CPU C6 > state in AC mode, we must modify the C-state mapping in ACPI tables. It > is not easy. And IMO it is meaningless(CPU C6 can save more power than > CPU C3. But it is not obvious). So not recommend to do so. > Of course if still hope to do so, please refer to the _CST object > defined in section 8 of ACPI 3.0 spec and custom DSDT should be used. Thanks Yakui. I have to say that I don't have any ACPI knowledge other than common hearsay so I have to learn ACPI from the beginning and I hope I could find some spare time to get and idea, at least. >From what I understood so far, the way to go would be the following: - Extract the ACPI tables of my notebook - Read the spec and tweak the right entry - Convince the kernel to use the customized table Probably I could also read the ACPI tables when on battery just to load it when in AC mode? (I could then skip step 2 of understanding what I'm doing... ;-) For the effectiveness: I cannot say whether the power consumption is that big, the difference of the fan (not) getting on my nerves _is_ significant however. I just had the idea that the behaviour of the embedded controller for controlling the fan may also be different in AC vs. battery mode (the threshold temperatures), so I it's indeed not garantueed that using C6 vs. C3 alone does the trick. But I do hope so. Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
