[Letux-kernel] [Tinkerphones] CI20 - was Re: New LetuxOS Kernels and some tricks and thoughts

[Paul Boddie]

On Wednesday 12. June 2019 20.07.35 H. Nikolaus Schaller wrote:
> 
> Yes, that is sad, but not the most important issue. It may be even better
> to have the NAND as a fallback boot option if the SD card becomes broken.

I personally wonder about the point of NAND, ultimately, at least for this 
kind of board. If I were designing a board, I'd be tempted to only support 
removable media given that the onboard flash memory will ultimately 
deteriorate and be unusable.

[...]

> >> What I wonder is where the LEDs (LED0 .. LED3) near the Ethernet
> >> controller chip DM9000C are connected to... I could not locate them in
> >> the schematics...
> > 
> > Aren't they the MMC indicators?
> 
> I have never seen them being active...

With the 3.1.x kernels there are always some LEDs twinkling when the SD card 
is being read. I actually thought that they were hard-wired and that any SD 
card accesses would cause them to twinkle, but I guess that this isn't the 
case.

[...]

> I have neither observed reboot problems nor Ethernet not working.
> 
> Maybe the DHCP isn't working reliable on your setup. Or the Ethernet gets a
> random MAC address so that the IP address changes after every reboot. Do the
> LEDs built into the Ethernet socket blink and show activity?

Now that I try again it works just fine with the 5.1.8 kernel. So I imagine 
that I didn't wait long enough previously and was convinced that a lack of LED 
activity meant that the board had failed to boot, which wasn't the case.

This is a bit more encouraging, although I obviously haven't tested various 
other peripherals, but at least the networking functions as it did before.

Paul