Automatic device driver back-porting with media_build

[Mason <slash.tmp@free.fr>]

Hello everyone,

I have a TechnoTrend TT-TVStick CT2-4400v2 USB tuner, as described here:
http://linuxtv.org/wiki/index.php/TechnoTrend_TT-TVStick_CT2-4400

According to the article, the device is supported since kernel 3.19
and indeed, if I use a 4.1 kernel, I can pick CONFIG_DVB_USB_DVBSKY
and everything seems to work.

Unfortunately (for me), I've been asked to make this driver work on
an ancient 3.4 kernel.

The linuxtv article mentions:

"Drivers are included in kernel 3.17 (for version 1) and 3.19 (for version 2).
They can be built with media_build for older kernels."
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This seems to imply that I can use the media_build framework to
automatically (??) back-port a 3.19 driver to a 3.4 kernel?
This sounds too good to be true...
How far back can I go?

http://linuxtv.org/wiki/index.php/How_to_Obtain,_Build_and_Install_V4L-DVB_Device_Drivers

I find the instructions not very clear.

I have cloned media_tree and media_build. And I have my 3.4 kernel source
in a separate "my-linux-3.4" dir.

How am I supposed to tell media_build: "hey, the latest drivers are in this
"media_tree" dir, I'd like you to compile this one driver for the kernel in
this "my-linux-3.4" dir" ?

Note that media_build/linux has scripts which reference include/uapi which
did not exist yet in 3.4

Anyway, my confusion level is at 11. I'd be very grateful if anyone here
can clear some of it!

Regards.