uart: sifive: fix interrupt-driven transmission

A txcnt of zero prevents transmission, as transmit requires the number
of entries in the transmit fifo to be strictly less than the txcnt
value.  Set the default to 1.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
This commit is contained in:
Peter A. Bigot 2020-03-23 16:09:21 -05:00 committed by Anas Nashif
commit 93309317d0

View file

@ -36,7 +36,7 @@ config UART_SIFIVE_PORT_0_RXCNT_IRQ
config UART_SIFIVE_PORT_0_TXCNT_IRQ
int "Port 0 TX Interrupt Threshold Count"
default 0
default 1
depends on UART_SIFIVE_PORT_0
help
Port 0 TX Threshold at which the TX FIFO interrupt triggers.