diff options
| -rw-r--r-- | kernel/uart.c | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/kernel/uart.c b/kernel/uart.c index af571b1..e3b3b8a 100644 --- a/kernel/uart.c +++ b/kernel/uart.c @@ -92,22 +92,18 @@ uartputc(int c) for(;;) ; } - - while(1){ - if(uart_tx_w == uart_tx_r + UART_TX_BUF_SIZE){ - // buffer is full. - // wait for uartstart() to open up space in the buffer. - sleep(&uart_tx_r, &uart_tx_lock); - } else { - uart_tx_buf[uart_tx_w % UART_TX_BUF_SIZE] = c; - uart_tx_w += 1; - uartstart(); - release(&uart_tx_lock); - return; - } + while(uart_tx_w == uart_tx_r + UART_TX_BUF_SIZE){ + // buffer is full. + // wait for uartstart() to open up space in the buffer. + sleep(&uart_tx_r, &uart_tx_lock); } + uart_tx_buf[uart_tx_w % UART_TX_BUF_SIZE] = c; + uart_tx_w += 1; + uartstart(); + release(&uart_tx_lock); } + // alternate version of uartputc() that doesn't // use interrupts, for use by kernel printf() and // to echo characters. it spins waiting for the uart's |