diff options
| -rw-r--r-- | hw/char/cadence_uart.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index 3eeadb18fd..3bcaf2905d 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -233,8 +233,16 @@ static void uart_parameters_setup(UartState *s) static int uart_can_receive(void *opaque) { UartState *s = (UartState *)opaque; + int ret = MAX(RX_FIFO_SIZE, TX_FIFO_SIZE); + uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; - return RX_FIFO_SIZE - s->rx_count; + if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { + ret = MIN(ret, RX_FIFO_SIZE - s->rx_count); + } + if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { + ret = MIN(ret, TX_FIFO_SIZE - s->tx_count); + } + return ret; } static void uart_ctrl_update(UartState *s) |