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diff --git a/Documentation/blackfin/bfin-spi-notes.txt b/Documentation/blackfin/bfin-spi-notes.txt
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+SPI Chip Select behavior:
+
+With the Blackfin on-chip SPI peripheral, there is some logic tied to the CPHA
+bit whether the Slave Select Line is controlled by hardware (CPHA=0) or
+controlled by software (CPHA=1). However, the Linux SPI bus driver assumes that
+the Slave Select is always under software control and being asserted during
+the entire SPI transfer. - And not just bits_per_word duration.
+
+In most cases you can utilize SPI MODE_3 instead of MODE_0 to work-around this
+behavior. If your SPI slave device in question requires SPI MODE_0 or MODE_2
+timing, you can utilize the GPIO controlled SPI Slave Select option instead.
+In this case, you should use GPIO based CS for all of your slaves and not just
+the ones using mode 0 or 2 in order to guarantee correct CS toggling behavior.
+
+You can even use the same pin whose peripheral role is a SSEL,
+but use it as a GPIO instead.