Guest bobsmith Posted May 17, 2016 Posted May 17, 2016 So, the Linux Kernel 4.6 is out. Supposedly it comes with a lot of new ARM processor support. I'm excited about this. I'm not too knowledgeable when it comes to kernel development, especially with ARM devices. I guess the question is, what's it going to take to move the devices that use these supposedly newly supported chips up to 4.6? I'm somewhat keen on updating to a kernel that isn't approaching EOL.
tkaiser Posted May 17, 2016 Posted May 17, 2016 So, the Linux Kernel 4.6 is out. Supposedly it comes with a lot of new ARM processor support. I'm excited about this. I'm not too knowledgeable when it comes to kernel development, especially with ARM devices. Ok, then here you go. Take a look at Lamobo R1 please. This is one of the boards that's now officially supported by mainline kernel and that Armbian users run mainline kernel on since ages since the broader community Armbian is part of reverse engineered the power scheme, added missing hardware descriptions, created a working fex file for this device and a device tree description based on that and ported the OpenWRT driver for R1's broadcom switch IC to be used with mainline kernel: http://linux-sunxi.org/Lamobo_R1#Mainline_kernel What's the difference now? The .dts file we use since ages has now been sent upstream and is part of the official kernel sources. Does this mean everything's alright now? Of course not since no one can make use of this device without the switch driver that will never be accepted upstream. So the news that another device has been added to mainline kernel doesn't mean anything. Please read the last paragraph (and also the whole thread to understand how 'add device to kernel' works): https://groups.google.com/d/msg/linux-sunxi/3zB35Y7cJXc/a_2sYbP5CgAJ In other words: It's not that important what happens upstream since Armbian collects patches pretty soon and devices that still don't work when officially supported by kernel run almost a year now with every 4.x kernel released so far. That some ARM devices appear upstream now is sometimes just the result of being used with Armbian since months. So please understand that we do not update kernel version immediately since it takes some time to check what's not working any more and needs a fix, which patches are obsolete and which not and so on. What many people also don't know: We also have to take care of u-boot since for many features mainline kernel relies on hardware being setup correctly by u-boot is a basic requirement and since we're now also dealing with a new u-boot version it takes additional time to test through working combinations.
Igor Posted May 17, 2016 Posted May 17, 2016 If you already exposed Lamobo R1 as an example. One small but important add: networking (on router device ) is not operational without this patch since there is no switch driver in mainline kernel and also Openwrt patches are not working since 4.4
tkaiser Posted May 17, 2016 Posted May 17, 2016 If you already exposed Lamobo R1 as an example. One small but important add: networking (on router device ) is not operational without this patch since there is no switch driver in mainline kernel and also Openwrt patches are not working since 4.4 Thanks for the addition. I almost forgot that Zador fixed the driver so that the device can be used with more recent mainline kernels.
zador.blood.stained Posted May 17, 2016 Posted May 17, 2016 I almost forgot that Zador fixed the driver ...using this as base
tkaiser Posted May 17, 2016 Posted May 17, 2016 ...using this as base Ah, ok, then kudos to Werner Böllmann too. Anyway I hope that it's now a bit more clear that 'board xy now officially supported' doesn't mean that much sometimes and that the R1 switch driver changes necessary for 4.5 still work with 4.6 (that's how I understood it)
Recommended Posts