[SERIAL] Move interrupt-time spinlocking inside serial8250_handle_port()

All call sites for serial8250_handle_port() acquired the port spinlock
and released it afterwards.  This is a needless duplication of code.
Move the spinlocking inside serial8250_handle_port().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index ad20d2dd85d74e301045bb6737db167ac77b2dd3..56dcfd93bdc4a5d18b394bc84a585cb68f3bc35f 100644 (file)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1281,7 +1281,11 @@ static unsigned int check_modem_status(struct uart_8250_port *up)
 static inline void
 serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
 {
-       unsigned int status = serial_inp(up, UART_LSR);
+       unsigned int status;
+
+       spin_lock(&up->port.lock);
+
+       status = serial_inp(up, UART_LSR);
 
        DEBUG_INTR("status = %x...", status);
 
@@ -1290,6 +1294,8 @@ serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
        check_modem_status(up);
        if (status & UART_LSR_THRE)
                transmit_chars(up);
+
+       spin_unlock(&up->port.lock);
 }
 
 /*
@@ -1325,9 +1331,7 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *r
 
                iir = serial_in(up, UART_IIR);
                if (!(iir & UART_IIR_NO_INT)) {
-                       spin_lock(&up->port.lock);
                        serial8250_handle_port(up, regs);
-                       spin_unlock(&up->port.lock);
 
                        handled = 1;
 
@@ -1426,11 +1430,8 @@ static void serial8250_timeout(unsigned long data)
        unsigned int iir;
 
        iir = serial_in(up, UART_IIR);
-       if (!(iir & UART_IIR_NO_INT)) {
-               spin_lock(&up->port.lock);
+       if (!(iir & UART_IIR_NO_INT))
                serial8250_handle_port(up, NULL);
-               spin_unlock(&up->port.lock);
-       }
 
        timeout = up->port.timeout;
        timeout = timeout > 6 ? (timeout / 2 - 2) : 1;