[svlug] Introduction and proposition on ACPI !!!
fabriziobertocci at gmail.com
Thu Sep 9 12:07:36 PDT 2004
First of all, let me quickly introduce myself.
I've been working with Linux, since the early days where Slackware was
distributing this new hacker-oriented operative system in floppy
Today I'm running Linux in all my desktops and laptops at work, as
well as home (Windows is *NOT* an alternative... MacOS X is...)
I think it's time to actively do something instead of just sitting and
waiting (and praying sometimes) for somebody to implement the missing
piece (driver) I need for my PC.
Linux as it is today, it's robust, nice-looking, full of features, but
it still lacks of something very important that even Microsoft haven't
figure out how to manage it very well: full ACPI support.
Note: so far, it seems to me that only Apple's notebooks are managing
ACPI (or other power-related standards) better than anybody else...
ACPI may not be important if you run Linux on a desktop, but it is a
KEY FEATURE when you run on a laptop. Think for a moment what you
really need from a laptop that you don't care on a desktop:
- Read the battery status and receive warnings when battery are getting low.
- Reduce the power consumption by:
- turning off the monitor/LCD when not used
- turning off the hard disk when not used
- reduce the CPU speed when the processor load is low or even decide
to reduce the performance on your machine in order to save power (i.e.
you are writing emails: you don't need to run your processor at
- turn off power to some devices (i.e. USB) when not in use
- Control the fan in order to:
- avoid to fry your CPU
- reduce the power consumed
- Read the state of some special keys that usually are available only
on laptops, like sleep/hibernate, screen lid, power buttons.
- AND MOSTLY: you want to be able to suspend to RAM and suspend to
disk (what Windows call 'suspend' and 'hibernate').
Now... all the above features are implemented by the ACPI subsystem,
and unfortunately this is still something very fuzzy and not perfectly
I've been experimenting different kernel version on the following laptops:
 Sony PCG-FXA32
 Sony PCG-FX150
 Sony PCG-R505JE
 HP Pavilion zt??? ( I don't remember the exact model)
 Sony PCG-505F
The results are very discouraging: only on one laptop  I was able
to do suspend-to-ram (through APM, not ACPI). On some of them I didn't
even have fan or battery or processor throttling control.
FYI, my main development machine is  where I can succesfully
suspend to disk (ACPI S4) and resume with no issues, and all the other
ACPI features are fully supported (hacked kernel 2.4.21).
It seems the problem is mostly related to the computer manufacturer
that always ship the unit with a buggy or partially implemented BIOS.
They solve the problem of sleep/suspend by asking users to upgrade the
BIOS (I've already killed one computer by doing this), or patching M$
Question and/or proposition:
Would it be very nice to have (or to start) a central repository where
people can submit their experience with their laptops on the ACPI
issue described above.
There are some websites out there (www.linux-laptops.com) that talks
about installing linux on laptops, but the information provided is
most of the time useless or poorly written.
I would like to find a place where I can see which laptop model works
better with Linux for example... (The Sony PCG-505F is probably a 10
years old machine... so is NOT an answer here)
I don't mind creating a website and start working on some front-end
for that... this can also be a good opportunity to promote the SVLUG
around the community...
What do you think?
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