[OpenWrt-Devel] [PATCH] ath79: switch to kernel 5.4

[Paul Blazejowski]

-------- Original Message --------
Subject: Re: [OpenWrt-Devel] [PATCH] ath79: switch to kernel 5.4
From: <mail at adrianschmutzler.de>
To: 'Stefan Lippers-Hollmann' <s.l-h at gmx.de>
Date: 6/27/2020, 6:48:05 AM

>>>> See here for some more details:
>>>> https://bugs.openwrt.org/index.php?do=details&task_id=2928
>>>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94506
>>>
>>> What's the status on this issue? Is it still there, and do we
>>> still have a
>> blocker for 5.4 on ath79?
>>
>> This issue is still open as of yesterday's master/
>> r13611-3f27a6e640, tested on both tl-wdr3600 and tl-wdr4300 with
>> kernel v5.4.48. The device bootloops very early and in close
>> succession, requiring tftp recovery[0].
>
> I think we should find some way to go on here. ath79 is quite a big
> target, and even after having it switched to 5.4 one should give it
> some time for tests and possible other necessary fixes before
> thinking about branching a release. So far, I see three possible
> options:
>
> 1. Just use Hauke's hack

It does not work anymore (for me at least) see #2

> 2. Use a different GCC version for the target, since problems are
> limited to 8.4.0

GCC 9.3.0 works with kernels up to 5.4.32 anything after and up to
5.4.49 will bootloop so this leads me to believe that this issue lies
also in kernel.

> 3. Find out the real reason for the problem

That's the problem here, the issue is not easy to find but everyone
gets it with no real fix (other thank flipping gcc versions in the
build for a while until it caches up again producing bootloop).

>
> Am I getting this right? Any opinions or additional ideas?

What worked for me in the initial report to the mailing list was to use
this patch from Kevin's staging tree [1] (modified for kernel 5.4, and
building with any gcc version on a clean checkout).
>
> Best
>
> Adrian
>

Cheers,
-paul

[1]
https://git.openwrt.org/?p=openwrt/staging/ldir.git;a=commit;h=2327a4deb
2941f0b59c0f1a8affd109a3262c753