Armbian H3 mainline vs. backporting module to legacy

[thesign]

I am using the latest Armbian version with a legacy kernel on my M2+ board. The Armbian forum has already been a great source of help.

Now I am facing a new issue:
- for my setup the IPv6 NAT netfilter module is required, which was introduced in Kernel 3.7

So in my understanding I have two options:

a) backport the kernel module(s) to the legacy Kernel by customizing the armbian build process

switch to the mainline Kernel

The mainline kernel for H3 boards seems to lack support for Gigabit ethernet and in general still remains no recommended for potential overheating problems?

Thus, I guess I have to get working on the Kernel module backports. Do you have any pointers for me? Is this issue better placed in another sub-forum?

thank you guys!

[thesign]

I am not sure if i brought up a painful subject in my question regarding the vanilla/mainline kernel? I guess @tkaiser and @Igor can't also wait for the vanilla kernel to be completed ;-)

In the meantime I will try my best to backport the (niche) features from Kernel 3.7. Any pointers to helpful documentation are more than welcome.

[zador.blood.stained]

Backporting is possible in theory, but in your case it may turn from a single module to a huge chunk of the kernel's netfilter subsystem. There are no tutorials for these procedures AFAIK, you just have to find the relevant commits with their dependencies and see what changes may be needed to use this code on the older kernel code base.

 

Regarding mainline - Ethernet is supported (but not without some issues that can't be fixed right now) and thermal throttling works too. The problem here is that M2+ Armbian configuration is not maintained, so DVFS and THS configuration is not present in the Device Tree for this board.

[tkaiser]

7 minutes ago, thesign said:

I am not sure if i brought up a painful subject in my question regarding the vanilla/mainline kernel?

 

Nope, I just skip threads that mention crappy hardware, I skipped reading your initial post when I read 'M2+ board'

 

FYI: I use GBit Ethernet on this board for almost a year now when we unfortunately added this board to Armbian (see OS images here: http://linux-sunxi.org/Banana_Pi_M2%2B#OS_images). It's prone to overheating and not really supported with mainline kernel and I believe Armbian still limits max cpufreq there to 816 MHz when using vanilla kernel? Anyway, don't care that much...

[zador.blood.stained]

2 minutes ago, tkaiser said:

I believe Armbian still limits max cpufreq there to 816 MHz when using vanilla kernel?

I don't see any limits in M2+ u-boot config patch, so even if it was there it fell out at some point, so we are back to the 1008 MHz (if I remember correctly) default.

[hojnikb]

Maybe 816Mhz is the max sustained frequency over a longer period of time. Every h3 board otherwise should hit at least 1.0Ghz on short bursts, if only there aren't any power related issues.

[tkaiser]

2 hours ago, zador.blood.stained said:

I don't see any limits in M2+ u-boot config patch, so even if it was there it fell out at some point, so we are back to the 1008 MHz (if I remember correctly) default.

 

https://github.com/igorpecovnik/lib/commit/96e7b00999f66dadf94563bf0d9f5f87e2fdc5fe

 

Consequences for legacy images: Boot times might increase by 0.3 seconds (1008 vs. 816 MHz until cpufrequtils take over). With mainline M2+ owners should be save again even in worst case situations.

[thesign]

I agree with @tkaiser that the M2+ board could have been better engineered. :-D
It seems to me that the Raspberry Pi remains to be the only affordable hardware with proper software support; wonder if they are going to release a gigabit version soon.

I have a naive question regarding my initial request:
@zador.blood.stained in order to port the chunk of netfilter changes back to the legacy kernel: should I diff the corresponding directories in the armbian sources folder against the official Linux kernel repo (tagged with 3.7)? Or do I need to diff against a "different" kernel source?

P.S: Sorry for the late replies, It seems I never receive any notifications for updates on this forum thread.

[Igor]

1 hour ago, thesign said:

It seems I never receive any notifications for updates on this forum thread.

SMTP daily sending limit exceeded once this week. Need to upgrade to some reliable service..