#use wml::tmpl::main title="JVC MP-XP7250DE and Linux"
<h1>Linux on a JVC MP-XP7250DE</h1>

<p>I recently upgraded my laptop from a <A href="$(ROOT)/jvcmp-xp7210de.html">JVC MP-XP7210DE</A> to its follow-up model, XP7250.</P>
<P>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.</p>
<H2>Installation</H2>
<p>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.</p>

<H2>USB</H2>
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.  <A href="$(ROOT)/xp7250-usb.patch">Here</A>
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.</p>

<H2>Built-in Wireless LAN!</H2>
Oh yes, this so rocks!  Did I already say that I like it?  Hmm, probably.<BR>
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
<A href="http://www.linux-wlan.com/linux-wlan/index.html">Linux-wlan-ng Project</A>, 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.</p>

<H2>Battery lifetime</H2>
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.

<H2>X Windows</H2>
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.