diff options
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/8250.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 6d0ce64163e..ea41f262645 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1868,6 +1868,7 @@ static int serial8250_startup(struct uart_port *port) } if (is_real_interrupt(up->port.irq)) { + unsigned char iir1; /* * Test for UARTs that do not reassert THRE when the * transmitter is idle and the interrupt has already @@ -1881,7 +1882,7 @@ static int serial8250_startup(struct uart_port *port) wait_for_xmitr(up, UART_LSR_THRE); serial_out_sync(up, UART_IER, UART_IER_THRI); udelay(1); /* allow THRE to set */ - serial_in(up, UART_IIR); + iir1 = serial_in(up, UART_IIR); serial_out(up, UART_IER, 0); serial_out_sync(up, UART_IER, UART_IER_THRI); udelay(1); /* allow a working UART time to re-assert THRE */ @@ -1894,7 +1895,7 @@ static int serial8250_startup(struct uart_port *port) * If the interrupt is not reasserted, setup a timer to * kick the UART on a regular basis. */ - if (iir & UART_IIR_NO_INT) { + if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) { pr_debug("ttyS%d - using backup timer\n", port->line); up->timer.function = serial8250_backup_timeout; up->timer.data = (unsigned long)up; |