quoted

It appears that all DMA faults are related to a fixed address,
0xffffa000. Is this address something special?

Also what does below message mean from a SPI driver's perspective?

"applespispi-APP000D:00: Error writing to device: 01 0e 00 00"

I am asking this because the IOMMU fault messages are about DMA Reads
(device raised memory read), while above message complains failing to
write to device.

When sending a command to the peripheral device applespi expects it to
acknowledge successful transfer with

	static u8 status_ok[] = { 0xac, 0x27, 0x68, 0xd5 };

but we are getting "01 0e 00 00" instead.

See applespi_check_write_status() in drivers/input/Keyboard/applespi.c

Thanks.

Since its working with `iommu.passthrough=1`, probably disable iommu for this hardware (if possible)?

Although there must be some other fix since it was working without passthrough before.