uartlite: support shared interrupt lines

Adapt isr to work with shared interrupt lines.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/serial/uartlite.c b/drivers/serial/uartlite.c
index 5d3a573d6994..377f2712289e 100644
--- a/drivers/serial/uartlite.c
+++ b/drivers/serial/uartlite.c
@@ -154,17 +154,22 @@ static int ulite_transmit(struct uart_port *port, int stat)
 static irqreturn_t ulite_isr(int irq, void *dev_id)
 {
         struct uart_port *port = dev_id;
-        int busy;
+        int busy, n = 0;
 
         do {
                 int stat = readb(port->membase + ULITE_STATUS);
                 busy  = ulite_receive(port, stat);
                 busy |= ulite_transmit(port, stat);
+                n++;
         } while (busy);
 
-        tty_flip_buffer_push(port->state->port.tty);
-
-        return IRQ_HANDLED;
+        /* work done? */
+        if (n > 1) {
+                tty_flip_buffer_push(port->state->port.tty);
+                return IRQ_HANDLED;
+        } else {
+                return IRQ_NONE;
+        }
 }
 
 static unsigned int ulite_tx_empty(struct uart_port *port)
@@ -221,7 +226,7 @@ static int ulite_startup(struct uart_port *port)
         int ret;
 
         ret = request_irq(port->irq, ulite_isr,
-                          IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "uartlite", port);
+                          IRQF_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port);
         if (ret)
                 return ret;