Vaio tips for Debian Squeeze (Shallow Thoughts)

Akkana's Musings on Open Source Computing, Science, and Nature.

Sat, 27 Aug 2011

Vaio tips for Debian Squeeze

I switched to the current Debian release, "Squeeze", quite a few months ago on my Sony Vaio laptop. I've found that Squeeze, with its older kernel and good attention to power management (compared to the power management regressions in more recent kernels), gets much better battery life than either Arch Linux or Ubuntu on this machine. I'm using Squeeze as the primary OS at least until the other distros get their kernel power management sorted out.

I did have to solve a couple of minor problems when switching over, though.

Suspend/Resume quirks

The first problem was that my Vaio TX650 would freeze on resuming from suspend -- something that every other Linux distro has handled out of the box on this machine.

The solution turned out to be simple though non-obvious, apparently a problem with controlling power to the display:

sudo pm-suspend --quirk-dpms-on

That wasn't easy to find, but ever since then the machine has been suspending without a single glitch. And it's a true suspend, unlike Ubuntu Natty, which on this machine will use up a full battery if I leave it suspended all day -- Natty uses nearly as much power when suspended as it does running.

Adjusting screen brightness: debugging ACPI

Of course, once I got that sorted out, there were the usual collection of little changes I needed to make. Number one was that it didn't automatically handle brightness adjustment with the Fn-F5 and Fn-F6 keys.

It turned out my previous technique for handling the brightness keys didn't work, because the names of the ACPI events in /etc/acpi/events had changed. Previously, /etc/acpi/events/sony-brightness-down had contained references to the Sony I/O Control, or SPIC:

event=sony/hotkey SPIC 00000001 00000010
action=/etc/acpi/sonybright.sh down
That device didn't exist on Squeeze. To find out what I needed now, I ran acpi-listen and typed the function-key combos in question. That gave me the codes I needed. I changed the sony-brightness-down file to read:
event=video/brightnessdown BRTDN 00000087 00000000
action=/etc/acpi/sonybright.sh down

It's probably a good thing, changing to be less Sony-specific ... but as a user it's one of those niggling annoyances that I have to go chase down every time I upgrade to a new Linux version.

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[ 11:07 Aug 27, 2011    More linux/laptop | permalink to this entry | comments ]
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