uartlite: support shared interrupt lines
Peter Korsgaard [Wed, 9 Sep 2009 14:54:04 +0000 (16:54 +0200)]
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>

drivers/serial/uartlite.c

index 5d3a573..377f271 100644 (file)
@@ -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;