spi: spi-fsl-dspi: Avoid reading more data than written in EOQ mode

If dspi->words_in_flight is populated with the hardware FIFO size,
then in dspi_fifo_read it will attempt to read more data at the end of a
buffer that is not a multiple of 16 bytes in length. It will probably
time out attempting to do so.

So limit the num_fifo_entries variable to the actual number of FIFO
entries that is going to be used.

Fixes: d59c90a2400f ("spi: spi-fsl-dspi: Convert TCFQ users to XSPI FIFO mode")
Signed-off-by: Vladimir Oltean <[email protected]>
Tested-by: Michael Walle <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>
1 file changed