spi: fsl-espi: make better use of the RX FIFO
So far an interrupt is triggered whenever there's at least one byte
in the RX FIFO. This results in a unnecessarily high number of
interrupts.
Change this to generate an interrupt if
- RX FIFO is half full (except if all bytes to read fit into the
RX FIFO anyway)
- end of transfer has been reached
This way the number of interrupts can be significantly reduced.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed