Does the Linux 4.9.113 kernel in CoreELEC 220.127.116.11 have an artificially low maximum frequency “compiled in” for the C4?
Per this C4 product page,
Another big improvement is a faster SPI bus interface with a maximum frequency of about 100MHz.
From some experimentation, though, I’m not sure it can be set much faster than ~8 MHz. If you’re interested, please see my posting on the Odroid forum:
Question on C4 SPI frequency
Also curious, as I note in that posting, is that I can’t get Odroid’s little spidev utility to fail, even trying ludicrous speeds. (“They’ve gone to plaid!”)