Linux kernel 6.1 or 6.6 for OpenWrt 24.x release?

[Christian Marangi (Ansuel)]

Il giorno sab 3 feb 2024 alle ore 16:58 Hauke Mehrtens
<hauke at hauke-m.de> ha scritto:
>
> On 2/3/24 15:31, Paul D wrote:
> > On 2024-02-03 13:06, Hauke Mehrtens wrote:
> >> Hi,
> >>
> >> I track the status of the Linux kernel 6.1 migration in this github
> >> issue: https://github.com/openwrt/openwrt/issues/14546
> >>
> >> There are still many targets on kernel 5.15 without testing support
> >> for kernel 6.1 in OpenWrt master. I assume that we need at least 4
> >> months to get everything to 6.1 and more or less stable. Kernel 6.1
> >> support is also missing for some important targets like lantiq,
> >> realtek and ramips.
> >>
> >>
> >> Which kernel should we use for the next major OpenWrt release?
> >> We have two options and I would like to get some feedback on these:
> >>
> >> 1. Do the OpenWrt 24.X release with kernel 6.1. Branch off when all or
> >> most of the targets are on kernel 6.1 by default.
> >> 2. Do the OpenWrt 24.X release with kernel 6.6. Branch off when all or
> >> most of the targets are on kernel 6.6 by default. Do not do any stable
> >> OpenWrt release which supports kernel 6.1.
> >>
> >> Doing a OpenWrt release with multiple kernels cases too much
> >> maintenance effort from my point of view based on previews experience.
> >>
> >>
> >> I think with kernel 6.1 we can branch off at around May 2024. With
> >> kernel 6.6 we could probably branch off around September 2024. The
> >> final release will be out about 2 to 4 months later.
> >
> > Do a release using 6.6 - although from past experience this means no
> > OpenWrt 24.
> >
> > 6.6 likely means carrying fewer patches also.
> >
> > Does this give rise to the potential that some older devices get dropped?
>
> Linux kernel 6.6 will probably be 5% to 10% bigger than Linux kernel 6.1
> as I have seen it between other LTS kernel versions.
>
> Maintenance of kernel 6.6 will be easier because we have to carry less
> patches and we will be closer to upstream.
>
> I expect that using kernel 6.6 will push out the next release by about 4
> months. I expect that the first target with kernel 6.6 testing support
> will be in master in less than 1 month after we decide to use kernel 6.6
> for the next release.
>

The most problematic target are as usual the one with most downstream
patch... So everything brcm and ath79.

Mvebu is slow as it seems there is low interest in it but in theory it
should be easy to port... For everything IPQ I will take care of migrating
all of them.

If we decide for 6.6 we will have the situation of having 3 kernel version?