tags/ubuntu http://youkan.39mm.net/~nil/iki/tags/ubuntu/ Nil Panasonic Y5 and Linux http://youkan.39mm.net/~nil/iki/101010/Panasonic_Y5_Linux/ http://youkan.39mm.net/~nil/iki/101010/Panasonic_Y5_Linux/ Y5 debian en hardware laptop linux panasonic ubuntu Tue, 07 Aug 2007 01:54:18 +0200 2008-01-20T13:31:05Z

I bought a Panasonic Y5 laptop in Japan in August 2006; it's sometimes called Let's Note Y5 or Thoughbook Y5 in Japan or USA. This machine is a great laptop, light (1.5Kg), strong (supposed to resist to 100Kg), fast (CoreDuo), eco (5 to 7 hours on the battery), all-included (wifi, SD, CD/DVD-RW), high quality (good material and attention payed to the details). Here is a report on using Linux with it.

For reference and details on the hardware, you can consult the lspci and lshw reports.

I started using it with Ubuntu 6.06 Dapper Drake in August 2006. The support has improved since, and I currently use 7.10 Gutsy Gibbon, kernel version 2.6.22; these comment should me more or less true for Debian 4.0 Etch.

in short

  • (v) dual-core CPU : OK
  • (v) frequency scaling : OK
  • (v) throttling : OK
  • (v) sleeping to disk: OK
  • (x) sleeping to memory : no
  • (v) ACPI : OK
  • (!) battery : partial
  • (?) TPM : untested
  • (v) video : OK
  • (x) external screen : no
  • (!) hotkeys : partial
  • (v) touchpad : OK
  • (!) sound : partial
  • (v) ethernet : OK
  • (v) wireless : OK
  • (?) modem : untested
  • (v) DVD RW : OK
  • (v) SD card : OK
  • (?) PCMCIA : untested

BIOS

Good Phoenix BIOS (comparing with my previous crappy laptops), the options include:

  • boot from disk, CD, network, USB disk, USB key, USB floppy and more; works nice, I used it to boot from some minidistros (DSL, gparted and others) installed on a USB stick;
  • deactivate some hardware parts (modem, wifi, dual core, CD, pcmcia, ...) to save power; quite efficient;
  • TPM crypto options; details later.

CPU

Intel Core Duo 1.5GHz low voltage; the dual core is fully supported, the single core mode (BIOS switch) also.

I didn't find how to switch to single core at boot time with a kernel option (I know it's possible) or while operating (I think it's possible).

Frequency scaling works, with the cpufreq module + powernowd client, at 2 levels (1GHz and 1.5GHz).

For a long time I had problems at boot time (CPU lock, computer freezed) with previous kernels, when booting with the two cores and the wifi switched off; this happened sometimes, no clear condition, very annoying and obscure bug, with its esoteric and useless error message: [71:492208] Bug: soft lockup detected on CPU#0!.

This kernel bug has been reported, and there seems to be some kind of fix... The best solution if it happens to you is to reboot with wifi switched on during the boot sequence.

This CPU used to get quite hot (85°C in the summer night, always more than 65°C, often around 100°C in action time (video encoding, heavy computation..) I was surprised, but Intel states that the dangerous temperature is 125°C. Anyway, they also say that the maximum temperature for optimal operation is 100°C...

I managed to limit this phenomenon by using thermal paste to improve heat exchange between CPU and cooler; it seems that the original one was low-quality. Now, my CPU stays under 50\302\260C in normal operating conditions.

You can also use CPU throttling, which basically means limiting the number of instructions the CPU handles per cycle; it's not frequency scaling, and it's specifically designed to reduce heat, while frequency scaling is here to save on the batteries.

This goes through /proc/acpi/processor/CPU0/throttling and works fine. Here is a tiny script to throttle in percentage, and another one to automatically limit the temperature with throttling. Run the last one when you launch something heavy, that will take time, and you want to limit the CPU temperature even it it means slower computations.

RAM

1Gb max, 512Mb is soldered on the motherboard, which is always a bad idea; my last laptop died of RAM failure, and the failing part was soldered on the board, so the machine was unusable, and repairing impossible.

Well, until now, no problem with the RAM.

HD

The disk is a Toshiba 60GB drive , protected against shocks by some rubber pads. Nothing to say, it just works. No problem.

No special hdparm setting improved the performances.

$ sudo hdparm -Tt /dev/sda
/dev/sda:
 Timing cached reads:   1466 MB in  2.00 seconds = 732.91 MB/sec
 Timing buffered disk reads:  104 MB in  3.04 seconds =  34.26 MB/sec

CD/DVD drive

It's a nice combo, read-write in any CD/DVD format. Two interesting details:

  • it's a clam-shell drive, opening from the top; this saves weight and allows for a very slim machine;
  • the drive is powered up only if you use it; this saves power, and makes no problem for its recognition by linux as a device.

Screen

The LCD screen is a 1400x1050 LCD screen; Xorg recognises it and can use the full resolution with the ''915resolution'' utility. Brightness and contrast are not wonderful, but quite usable except with a source of bright light behind you.

External screen switch remains to be accomplished; a BIOS switch allows to use an external screen from boot-time if detected, and it works, but I couldn't succeed in switching on-the-fly. Note that I still didn't try the new XRandR tools.

GPU

Decent 3D acceleration, with an official free driver from Intel; I'm not a gamer, so I can't compare its performances with other models (Nvidia, ATI), but if fullfills all my needs for 3D imaging. The only problem would be that it tends to get quite hot when intensively used.

Keyboard

Japanese keyboard in my version, with its useful extra keys if you use IME for non latin scripts.

Note : I always fould SCIM difficult to configure and use; finally, UIM suits me better.

The correct keymap for this japanese version is ''jp106''.

Touchpad

Works, it's a nice round touchpad. Yes, round! This seemed weird at the beginning, but I love it now; with a few X configuration, you get a wonderful circular scroll, very comfortable to scroll in teminal, browsers, to zoom in/out, to move forward/backwards, and so on.

Ethernet

The 10/100 Realtek network interface works out of the box. Perfect.

Wireless

The 802.11abg Intel 3945 WiFi interface works out of the box, no problem except for packet injection (the driver doesn't support it).

Modem

Don't know, never used. I guess it's a 56K v92 WinModem.

Power and battery

The battery manager provides 2 operating modes:

  • normal mode, filling it up to 100% when charging
  • long life mode, limiting the charge to 80%, in order to expand the battery life

The only way to switch between these two modes is from a Windows utility; this was the reason why I kept a Windows partition for quite a long time; I gave up recently, and use now another harddisk with a basic WinXP install when I want to switch.

The minimum energy use and battery autonomy of the laptop, while being completely idle, is, as reported by ''acpi'':

  • max brightness: 12W - 4.5 hours
  • min brightness: 7W - 7.5 hours

Enabling or disabling dual core and all the hardware extensions doesn't really impact the idle power use, +/- 1W.

/!\ to be expanded/continued /!\

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