diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 2164290cbd31..2e7000f79b03 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -311,7 +311,11 @@ static const struct serial8250_config uart_config[] = { /* Uart divisor latch read */ static int default_serial_dl_read(struct uart_8250_port *up) { - return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8; + /* Assign these in pieces to truncate any bits above 7. */ + unsigned char dll = serial_in(up, UART_DLL); + unsigned char dlm = serial_in(up, UART_DLM); + + return dll | dlm << 8; } /* Uart divisor latch write */ @@ -1297,9 +1301,11 @@ static void autoconfig(struct uart_8250_port *up) serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); - scratch = serial_in(up, UART_IIR) >> 6; - switch (scratch) { + /* Assign this as it is to truncate any bits above 7. */ + scratch = serial_in(up, UART_IIR); + + switch (scratch >> 6) { case 0: autoconfig_8250(up); break; |