Hi @Nick A — great work on these builds, I've been testing both your BSP (v0.6.4, kernel 6.6.98) and Mainline (V0.1, kernel 6.18.19) images on a Cubie A7Z with a custom carrier board. Both work well for general use.
I've been trying to get a W5500 SPI-to-Ethernet chip working on SPI2 and ran into a consistent issue across both kernels that might be worth looking at.
Issue: sunxi-spi-ng child device never gets probed
The SPI2 controller itself initialises correctly on both kernels:
sunxi-spi-ng 2542000.spi: probe success (Version 2.5.4)
But the child device (spi2.0) never gets a driver bound to it. The w5100-spi driver is loaded, the modalias matches (spi:w5500), fw_devlink=off is set, yet:
echo spi2.0 | tee /sys/bus/spi/drivers/w5100/bind → No such device
echo spi2.0 | tee /sys/bus/spi/drivers_probe → accepted, no effect, zero dmesg output
Dynamic debug enabled (module w5100 +p) → zero probe activity
This reproduces on:
Radxa BSP kernel 5.15.147-21-a733 (official r6 image)
Your BSP build kernel 6.6.98
Your Mainline build kernel 6.18.19
All three use the same spi-sunxi-ng.ko / spi_sunxi_ng driver (same allwinner,sunxi-spi-v1.3 compatible string).
Hardware confirmed good: the same W5500 chip on the same physical pins works perfectly when an ESP32-S3 is plugged in instead — DHCP, real network data, everything. Raw spidev access on the Radxa also reads correct W5500 registers. The bug is specifically in sunxi-spi-ng's child device registration preventing any driver from binding.
Overlay used:
dts
/dts-v1/; /plugin/; &spi2 { status = "okay"; sunxi,spi-bus-mode = <1>; sunxi,spi-cs-mode = <0>; eth0: ethernet@0 { compatible = "wiznet,w5500"; reg = <0>; spi-max-frequency = <20000000>; }; };
Note: sunxi,spi-bus-mode = <0> is rejected at probe time with error -22 ("unsupport hw bus mode 0x0"), so <1> is the only accepted value.
Has anyone else seen this? Is there a known workaround for getting SPI child devices to bind under sunxi-spi-ng on A733?
