bfin: discard invalid data and clear RXS in bf5xx spi driver
There may be dirty data in RDBR, so we should discard invalid data.
This operation also clears RXS bit in STAT register.
Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c
index 0fa131b..a9a4d92 100644
--- a/drivers/spi/bfin_spi.c
+++ b/drivers/spi/bfin_spi.c
@@ -248,6 +248,8 @@
static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
uint bytes)
{
+ /* discard invalid data and clear RXS */
+ read_SPI_RDBR(bss);
/* todo: take advantage of hardware fifos */
while (bytes--) {
u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);