Robert:
OK, I have a overlay bug for you.

I have a SPI0 application, where I don't want to use the CS0 output from 
the peripheral, but would rather bit bang the chip select line CS0 on the 
same pin as a GPIO.  I have three SPI devices sharing the SPI bus, so I 
need to have three chip select lines, that are all GPIO lines, but the 
first one is P9.17.  (The BBB does not pin out peripheral CS1 line, so you 
need to do something like this, anytime you have more than two SPI slaves.)

On kernel 3.14, all I had to do was comment out the appropriate lines 
regarding P9.17 in the "BB-SPIDEV0-00A0.dts" and the SPI  interface would 
not claim the CS line, and I could then claim it as a GPIO and everything 
worked fine.

Under kernel 4.1, doing the same edit to the file and creating a ".dtbo", 
even though I only reference the three core bus lines (clock, DI and DO) in 
the ".dts" the spi driver still claims all four lines, including the CS0, 
and I have a conflict on P9.17, so my GPIO ".dtbo" won't load, and things 
go downhill from there.

The problem pin is P9.17, aka pin95, offset 0x17c.

Debian Image 2015-06-17
uname -a= Linux BBB2 4.1.0-rc8-bone9 #1 Wed Jun 17 00:05:43 UTC 2015 armv7l

--- Graham 

==

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