diff options
Diffstat (limited to 'drivers/serial/8250.c')
| -rw-r--r-- | drivers/serial/8250.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 342e12fb1c2..9ccc563d873 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1908,15 +1908,23 @@ static int serial8250_startup(struct uart_port *port) * kick the UART on a regular basis. */ if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) { + up->bugs |= UART_BUG_THRE; pr_debug("ttyS%d - using backup timer\n", port->line); - up->timer.function = serial8250_backup_timeout; - up->timer.data = (unsigned long)up; - mod_timer(&up->timer, jiffies + - poll_timeout(up->port.timeout) + HZ / 5); } } /* + * The above check will only give an accurate result the first time + * the port is opened so this value needs to be preserved. + */ + if (up->bugs & UART_BUG_THRE) { + up->timer.function = serial8250_backup_timeout; + up->timer.data = (unsigned long)up; + mod_timer(&up->timer, jiffies + + poll_timeout(up->port.timeout) + HZ / 5); + } + + /* * If the "interrupt" for this port doesn't correspond with any * hardware interrupt, we use a timer-based system. The original * driver used to do this with IRQ0. |