[Letux-kernel] MIPS-Generic Kernel on CI20

[H. Nikolaus Schaller]

> Am 24.05.2025 um 12:40 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
> 
> AFAIR we had the same initially for x1600/x2000 and it was something in clock setup.

Indeed on April 29th:

>>> With that fixed, I can now boot up to:
>>> 
>>> calibrate_delay_converge()
>>> 
>>> So let's see what happens there (or does not happen but should).
>> 
>> We experienced issues in this area at the end of January 2024, according to my 
>> records. I seemed to make progress with my paulb-letux-6.7-rc8-tcu branch at
> 
> Yes, indeed it looks like a repetition of issues...
> 
>> the time, and I believe that such issues might have been related to interrupt 
>> handling.
> 
> What I wonder is that the sudomaker-6.1.y kernel shows exactly the same issue
> and I assumed that they have it working on the halley5 board...
> 
> Ah, that may be an interesting check: do they have some special trick in the
> halley5.dts?
> 
> Indeed. They define the extclk frequency board specific and have assigned
> clocks for ost32 and ost64. This is something I do not yet have in the lx20.dts
> or "our" x2000.dtsi. And I use the lx20.dts also on the sudomaker kernel...

And it was this patch:

https://git.goldelico.com/?p=letux-kernel.git;a=blobdiff;f=arch/mips/boot/dts/ingenic/x2000.dtsi;h=dedc77bce6f1f4e4558380fe4b8f44309d2f1af8;hp=514caa7e71c88ed00e8cc8529329a078d823cf47;hb=e90186c4f3731df8cbbabcabaf41f60979ca05cb;hpb=38f0881b147fb422a761c28e2fe546b26c2e2e66

We may need something similar for the jz4780.dtsi although there are already definitions in ci20.dts:

https://git.goldelico.com/?p=letux-kernel.git;a=blob;f=arch/mips/boot/dts/ingenic/ci20.dts;h=e41ed48d944e96db20f5d009c3fdda3b9e378a15;hb=e3551dd3ebe6efaabbfd569b015e4164d1dfc448#l294

What makes me wonder a little is why appending this dtb in the ci20 specific kernel makes
it boot. Perhaps there is some small but important diff in the defconfig.

BR,
Nikolaus