Franz Böhm wrote:
Also all Atheros based systems with binary drivers from Atheros itself or SDK's from third party vendors only work with particular (quite old) kernel versions. Perhaps you are able to build with newer kernel but it's much more difficult to get support from the chip manufacturer this way.
Using open source drivers instead is not always an opinion because it's very hard to comply with radio regulations and get your product certified. This is why I think it's somehow also important for BATMAN to support older kernels.
Yes, commercial support is a big problem. The atheros driver (targeted for 2.6.15) can be ported to with reasonable effort to a kernel supported by batman-adv. But as you stated above the upstream support maybe will be gone afterward.
...do we really trust devices running really old kernels? There must be a well educated and hard working support team behind that kernel to keep it working. Not that bugs come over time, but bugs are found over time and must be fixed or otherwise some people will have more fun than you with these "features".
So we have different possibilities, but the most important one should be the requirements of the actual developers. Both Marek and Simon use batman-adv on different kernels and have special requirements on kernel versions they must support.
We can use openwrt as extra information what should be supported. Currently I see kernels from 2.6.25-2.6.34.
To come back to the security consideration: Usually the kernel folks support the last kernel only with security fixes and other bug fixes. This isn't sufficient for people which run a specific kernel a long time (distributions for example). As result of these requirements a specific kernel version is maintained longer than others [1] ("LTS" if you want to name it in ubuntu- style). So the lowest kernel version number here is 2.6.27
I am not sure if we really want to check kernels of specific desktop/server distributions because they aren't our real target audience and kernels of distributions with a really long support time tends to have more in common with every other kernel but not with the vanilla kernel with the same version number.
Best regards, Sven
[1] http://www.kroah.com/log/linux/stable-status-01-2010.html