tree ac17c518f5357f051350af2833675af9cb913182
parent 4fbd8d194f06c8a3fd2af1ce560ddb31f7ec8323
author Maxime Chevallier <maxime.chevallier@smile.fr> 1516205725 +0100
committer Mark Brown <broonie@kernel.org> 1516273152 +0000
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spi: a3700: Clear DATA_OUT when performing a read

When performing a read using FIFO mode, the spi controller shifts out
the last 2 bytes that were written in a previous transfer on MOSI.

This undocumented behaviour can cause devices to misinterpret the
transfer, so we explicitly clear the WFIFO before each read.

This behaviour was noticed on EspressoBin.

Signed-off-by: Maxime Chevallier <maxime.chevallier@smile.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>