Corrupted audio when running on battery

[stevezsuzska]

I am running Puppy 4.2 on a Toshiba Portege 3110CT. When I run on mains power, audio is good but as soon as I disconnect the power and run from batteries, the audio breaks up to a weak crackling noise. Htop shows me that the processor is only about 50% utilised. Any ideas?

Thanks,

Steve

[AF Branden]

May be the laptops power saving features causing it which only go into effect when running off the battery, try disabling them. On my compaq laptop you have to go into the bios and do it.

[stevezsuzska]

Thanks for the reply. I had a look in the BIOS and could not see much on power saving. It's a very limited BIOS page. However, I tried inserting acpi=off in the kernel line of menu.lst in Grub, which had no effect. Then it occurred to me that due to the age of the laptop, ACPI might be turned off by default. So I tried acpi=force instead and this appears to have worked. Perhaps someone more knowledgable could explain why.

[Patriot]

Hmmm .....

A very brief and simplified notes:

Any bios pre-dates 2001 will switch kernel's acpi handling to off. This preset is defined during puppy kernel compile. You can of course, compile your own and push it back even further.

This acpi stuff is bios flags driven, basically used to allocate resources to internal hardware. The bios date cut-off is only as a guide. So, we still have options :

option off: turn it off
option force: turn it on
default on: depends on bios date and bios flags/features

There's still problematic acpi bios post 2001 ... most acpi bios back then were designed and tested for the windows platform ... to remedy this, the linux kernel now tries to use the windows acpi flags ...

It is what it is ... bios firmware used in the machines is beyond our control 99% of the time ...

I have an ibm p3 machine with year 2000 acpi bios. It needs acpi=force too .....


Rgds