JVC MP-XP7250DE and Linux

Linux on a JVC MP-XP7250DE

I recently upgraded my laptop from a JVC MP-XP7210DE to its follow-up model, XP7250.

The new model has 10GB more disk space, 128MB more RAM, USB 2.0 and a built-in wireless LAN adatopr. Those enhancements made the upgrade quite worthwhile for me.


This time, I used a USB CD/DVD-ROM to boot off a Debian Woody CD. Things worked out nicely, except that I had to explicitly disable the use of framebuffer console again, since the display was kind of distorted if framebuffer console was used.


It appears that current Linux kernels (v2.4 and v2.6) do not work with the USB 1.1 subsystem of this laptop without a little bit of modification. The standard ohci-hcd module of the Linux kernel performs a Host-Controller Takeover, which fails on the XP7250. I suspect this is due to some incompatibility in the BIOS. However, there are as of now no updates for the BIOS available, so to get a working USB 1.1 and 2.0, you need to patch your kernel. Here is a patch for linux 2.6.4. Note however, that this "soltuion" is very bad, and you should perhaps not use kernels patched in that way for other machines than the xp7250.

Built-in Wireless LAN!

Oh yes, this so rocks! Did I already say that I like it? Hmm, probably.
The built-in wireless LAN card of the xp7250 is connected internally via USB, and it is a Prism2.5 chipset based adaptor. This card is currently only supported by the Linux-wlan-ng Project, and not by the standard kernel yet. You need to download one of the latest development snapshots (I use 0.2.1pre20), and build/install it. The latest version of linux-wlan-ng in Debian does currently not yet support this USB card variant, so you will need to compile from sources.

Battery lifetime

The xp7210 already survived 4 hours of continuus usage, if treated with a bit of care (lowering processor speed via ACPI if appropriate). My experience with the xp7250 is that it even survives a little longer. I successfully used it for 4 hours and 30 minutes with one full charge straight, which is really pretty neat.

X Windows

Well, I should probably keep my mouth shut here, since I am really not the person to ask about X Windows Specifics, but just to let you know, the xp7250 uses a SiS630 graphics chipset, which does work with the sis driver of XFree86 4.3. I have had problems with earlier versions of XFree86, so make sure to use 4.3.
Last Modified: 2004-03-14 01:51:53
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