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path: root/drivers/serial/8250.c
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Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index a97f1ae11f7..9ccc563d873 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1885,7 +1885,7 @@ static int serial8250_startup(struct uart_port *port)
* the interrupt is enabled. Delays are necessary to
* allow register changes to become visible.
*/
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
if (up->port.flags & UPF_SHARE_IRQ)
disable_irq_nosync(up->port.irq);
@@ -1901,22 +1901,30 @@ static int serial8250_startup(struct uart_port *port)
if (up->port.flags & UPF_SHARE_IRQ)
enable_irq(up->port.irq);
- spin_unlock(&up->port.lock);
+ spin_unlock_irqrestore(&up->port.lock, flags);
/*
* If the interrupt is not reasserted, setup a timer to
* 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.