Patch 3/4 is the important one. Without it, reads and writes of certain lengths from spi-nor fails, and stuff at physical address 0x0 gets overwritten even if no input buffer is supplied (e.g. when sending a command).
Tested on an mpc8309-derived board. It would be nice if someone with access to the gazerbeam board can test that this doesn't break that - in particular, the "only do transfers that are multiple of 8 bits" part. Rasmus Villemoes (4): gazerbeam: add clocks property to SPI node mpc8xxx_spi: put max_cs to use mpc8xxx_spi: always use 8-bit characters, don't read or write garbage mpc8xxx_spi: implement real ->set_speed arch/powerpc/dts/gdsys/mpc8308.dtsi | 7 ++ drivers/spi/mpc8xxx_spi.c | 141 ++++++++++++++++------------ 2 files changed, 88 insertions(+), 60 deletions(-) -- 2.23.0