Gotcha: the SPI busses are used by the touchscreen controllers on the
expansion boards that support them, so if you don"t use touchscreens,
I recommend you disable them in the defconfig, to avoid conflicts (in
the 2.6.32 kernel the touchscreens entries were conditionally added to
the spi info array based on the defconfig values, so I just disabled

Unfortunately disabling the touchscreen in SW won't be enough. SPI can't be used on the external 40 pin header on a board which support touchscreen because of the way Gumstix has made the level conversion. SPI1_MISO (GPIO173) SPI1_NIRQ (GPIO114) is connected to a 164245 which always actively drives those signals.