Kernel update and Google Earth

[James Gray]

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Mark Allen Sheely wrote:
> Hi everyone,
> 
> After updating to 2.6.15-26-386, Google Earth gives me the following
> errors on startup:
> 
> do_wait: drmWaitVBlank returned -1, IRQs don't seem to be working
> correctly.
> Try running with LIBGL_THROTTLE_REFRESH and LIBL_SYNC_REFRESH unset.
> 
> When GoogleEarth does finally start up, it is unusably slow.  However,
> if I reboot into version 2.6.15-25-386, then  the application runs
> without a hitch.   This
> seems to suggest that something else needs updating along with the
> kernel, right?
> I did STFW, and what I found didn't make sense to me.  If anyone has any
> help to offer, I would very much appreciate it.
> Besides, helping me would be a welcome break from arguing about the
> freedom of Ubuntu :)

Even though the kernel version is the same, and the new one is just a
different build, it /possible/ the kernel interface for your graphics
driver is slightly different.  If you're running an nVidia or ATi binary
driver, try recompiling the the driver from the manufacturer's site.

The binary drivers use an open-source "shim" to hook into the kernel and
the binary component isn't *that* dissimilar to their Windows drivers.
It looks a little like this:

[Binary Blob] <-> [SHIM] <-> [Linux Kernel]

Now, if the communication between the shim and the kernel is slightly
different, but mostly the same, you'll probably only see errors when
very specific driver functions are called, and the rest of the time
everything works fine.  Just like you describe above.

Personally I avoided the "restricted" kernel modules from Ubuntu and
simply compiled my own IPW2200 and nVidia modules.  That way I stayed on
the bleeding edge and got all the nice new features (and occasionally
bugs!).  Also by recompiling the drivers when the kernel changes (which
isn't that often) you avoid these sort of weird problems as you're
making sure the shim and the kernel are talking the same dialect.

Of course if all that isn't something you're comfortable with, then by
all means use the Ubuntu restricted modules.  However, you might want to
file a bug with the maintainer for whatever video card you're using.

Cheers,

James
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