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Contact/Impressum

       
Fri, 04 Jul 2008
Submitting pcc_acpi for mainline inclusion

The last couple of days I've once again updated my kernel to current linux-2.6.git and I had to do the manual merge of the apparently abandoned original out-of-tree pcc_acpi.ko driver in order to get brightness control of the LCM on my Panasonic CF-R5 laptop.

I've tried to contact the original author multiple times during the recent years asking about his mainline inclusion plans, with no response so far. So this time finally I decided to submit the driver even without explicit wish by the original author. It was already GPL licensed, so no problems here.

However, the driver didn't yet support the backlight class device API, neither did it support user-configurable keymaps on the input device for the hotkeys. It furthermore added tons of new files to /proc with all the ugliness of writable proc files, and it didn't conform to the coding style at all.

Matthew Garrett was extremely helpful with his fast review, and I have just sent the 0.94 version to linux-acpi, hopefully the last one before kernel inclusion. I should have done this a long time ago, but it just didn't feel right to go ahead without the original author's opinion. However, the driver now doesn't really look like the old driver anymore, very little code left. So I feel like I have more moral right to go ahead with it now...

Of course I've only tested it on the CF-R5. Anyone with different Let's note models and versions: Please feel welcome to test it and send bug and success reports.

[ /linux | permanent link ]

Electrical installations in Taiwan

I haven't noted this here yet, but I'm in Taiwan again since two weeks ago. I also have two more weeks of Taiwan ahead, since I decided to stay a full month and go to a Chinese language school. Now don't expect too much, this is basically just to find out whether I really want to seriously learn about the language or not. Four weeks will not get me anywhere, at least not beyond pronunciation drills and very basic sentences + vocabulary.

Anyway let's get to the subject of my posting: During the last couple of days I actually spent a significant amount of time trying to find something that to me is the most normal thing: A 60W 220V light bulb with an E14 socket. But that would apparently only be normal in Europe. Here in Taiwan, the voltage typically is 110V at 60Hz, with US-style power sockets. Basically just like the US or Japan.

However, for some really strange and unknown reason, the particular apartment has both 3 phase 110V and 3 phase 220V. The power sockets are all 110V, whereas the fixed ceiling lights are all 220V.

So apparently sometimes people have 220V lights here, and you can get a limited selection of usual bulbs in 220V type, even though 90% of the light bulbs in the store would be 110V.

I've been to Carrefour, B&Q and Tsan-Kuen (all large super-stores in NeiHu). 220V was really rare, and neither of them had any E14 bulbs (independent of shape) for 220V. So after a lot of wasted time, I then decided that I'm just going to replace the entire lamp socket with an E27 type in order to accommodate a different lamp. My other option would have been to add another E14 socket in series and then use two 110V bulbs attached to 220V mains.

Now the really big question is: Why would anyone have the lighting at 220V whereas the power outlets are running1 at 110? This means you need separate infrastructure, separate lines, transformers, metering devices, circuit breakers, etc. And three simply is no point. I could understand 3-phase 220 is better than 3-phase 110 in case you want to use extremely high-power consumers.

[ /personal/taiwan | permanent link ]