diff options
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 3cf5c98013e4..547afde9fdda 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2088,8 +2088,8 @@ int serial8250_do_startup(struct uart_port *port) /* * Clear the interrupt registers. */ - serial_port_in(port, UART_LSR); - serial_port_in(port, UART_RX); + if (serial_port_in(port, UART_LSR) & UART_LSR_DR) + serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); @@ -2250,8 +2250,8 @@ dont_test_tx_en: * saved flags to avoid getting false values from polling * routines or the previous session. */ - serial_port_in(port, UART_LSR); - serial_port_in(port, UART_RX); + if (serial_port_in(port, UART_LSR) & UART_LSR_DR) + serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); up->lsr_saved_flags = 0; @@ -2344,7 +2344,8 @@ void serial8250_do_shutdown(struct uart_port *port) * Read data port to reset things, and then unlink from * the IRQ chain. */ - serial_port_in(port, UART_RX); + if (serial_port_in(port, UART_LSR) & UART_LSR_DR) + serial_port_in(port, UART_RX); serial8250_rpm_put(up); del_timer_sync(&up->timer); |