[Letux-kernel] Status LX16

[H. Nikolaus Schaller]

Hi all,
Today I finally managed to get WLAN working. Well, I don't even know what I changed, other than installing the latest letux-6.13-rc3 kernel...
So that main obstacle is removed.

What I also have worked on is to add some hints to the device tree that the esp-flasher can read out which gpios and UART to use.
Unfortunately it is not something that can be upstreamed at any time... It violates several rules on how device trees should be used.
I also thought about a special esp-flasher driver which could be a serdev for the UART. Unfortunately, the kernel hides the UART from /dev/tty
as soon as such an entry present in DTS, even if the driver is missing. So it is not possible to fall back to the above solution.

Anyways, I think there is only one thing not 100% clarified: USB-C OTG. I have some USB-C devices and cables which work
and others don't. And simply plugging into an USB-C port of a MacBook isn't reliable as well. What reliably works is to use an
USB-C to USB-A adapter and an USB-A to USB-C cable. But direction counts...

And some work only once if plugged in before the LX16 is powered on. After unplugging and replugging it no longer works.
This might be a hardware issue that the USB-C power controller chip and the power bridge from the second USB-C socket
to the OTG socket locks up and does not detect unplugging of the peripheral.

If we finally find a fix for the SPI speed and DMA issues, it is IMHO mature enough to be announced to some community
(well, which one?) and start upstreaming of our patches.

One other aspect which could be better than it is, is the management of the device tree for variants. We still have a single lx16.dtb
which must be compiled into the kernel binary. Even if we had multiple .dtb in /boot. I still have no idea how to manage that
better than we did so far with #if in the DTS file.

But everything is good enough now to build some units of version 0.4 early next year. And to share some of them with you
and Lumissil. And to start work on an LX20 prototype.

So I wish everyone a Merry Christmas and a Happy New Year.

Best regards,
Nikolaus