Comment 31 for bug 460857

@David (#30)

Unfortunately it looks like the drivers on the ftdi site may not work with newer versions of the kernel, including the kernel in karmic. The ftdi_sio.h and .c I grabbed were from the linux kernel tree (version 2.6.31.8). A number of changes seem to have been made without increasing the version number - lots of reformatting and rearrangement (which makes it hard to diff), but also a much longer list of supported device ids. Running the modified version of tz's makefile with the ftdi version also gives a list of errors which look like the result of changes to the usb structure in newer kernels (references to the fields tty and open_count that aren't in the usb_serial_port structure in the kernel headers). I'm not an expert in kernel drivers, however, so there may be an easy way to update this driver that I'm missing.

To be honest, I'm worried that you're grappling with an additional bug (e.g. a bug in the driver for your usb chipset) in addition to the FTDI bug the rest of us had. It sounds like the symptoms you are encountering are somewhat different than what the rest of us had, and the fix that worked for the rest of us (tz's) isn't working for you. I've been hesitant to suggest this, however, because I don't have a good suggestion of how to fix this new bug. Doing a search on "khubd karmic" turns up a lot of bugs with similar symptoms, many of which are unresolved. It's not clear to me which (if any) match the problem you're encountering, however; this looks like it may just be a common mode of failure.

It may be worth doing some additional searches based on your laptop model and usb chipset to see if any existing bug seems to match what you're seeing. If not, it may be worth opening a new bug.