+@@ -511,6 +551,34 @@
+ }
+
+ /*
++ * USART0 DCD Interrupt handler
++ */
++
++static irqreturn_t atmel_u0_DCD_interrupt(int irq, void *dev_id)
++{
++ struct uart_port *port = dev_id;
++ int status = at91_get_gpio_value(irq);
++
++ uart_handle_dcd_change(port, !(status));
++
++ return IRQ_HANDLED;
++}
++
++/*
++ * USART3 DCD Interrupt handler
++ */
++
++static irqreturn_t atmel_u3_DCD_interrupt(int irq, void *dev_id)
++{
++ struct uart_port *port = dev_id;
++ int status = at91_get_gpio_value(irq);
++
++ uart_handle_dcd_change(port, !(status));
++
++ return IRQ_HANDLED;
++}
++
++/*
+ * Interrupt handler
+ */
+ static irqreturn_t atmel_interrupt(int irq, void *dev_id)
+@@ -587,6 +655,23 @@
+ return retval;
+ }
+
++ if (port->mapbase == AT91RM9200_BASE_US0) {
++ retval = request_irq(AT91_PIN_PA19, atmel_u0_DCD_interrupt, 0, "atmel_serial", port);
++ if (retval) {
++ printk("atmel_serial: atmel_startup - Can't get u0DCD irq\n");
++ free_irq(port->irq, port);
++ return retval;
++ }
++ }
++ if (port->mapbase == AT91RM9200_BASE_US3) {
++ retval = request_irq(AT91_PIN_PA24, atmel_u3_DCD_interrupt, 0, "atmel_serial", port);
++ if (retval) {
++ printk("atmel_serial: atmel_startup - Can't get u3DCD irq\n");
++ free_irq(port->irq, port);
++ return retval;
++ }
++ }
++
+ /*
+ * Initialize DMA (if necessary)
+ */
+@@ -603,6 +688,10 @@
+ kfree(atmel_port->pdc_rx[0].buf);
+ }
+ free_irq(port->irq, port);
++ if (port->mapbase == AT91RM9200_BASE_US0)
++ free_irq(AT91_PIN_PA19, port);
++ if (port->mapbase == AT91RM9200_BASE_US3)
++ free_irq(AT91_PIN_PA24, port);
+ return -ENOMEM;
+ }
+ pdc->dma_addr = dma_map_single(port->dev, pdc->buf, PDC_BUFFER_SIZE, DMA_FROM_DEVICE);
+@@ -636,6 +725,10 @@
+ retval = atmel_open_hook(port);
+ if (retval) {
+ free_irq(port->irq, port);
++ if (port->mapbase == AT91RM9200_BASE_US0)
++ free_irq(AT91_PIN_PA19, port);
++ if (port->mapbase == AT91RM9200_BASE_US3)
++ free_irq(AT91_PIN_PA24, port);
+ return retval;
+ }
+ }
+@@ -701,6 +794,10 @@
+ * Free the interrupt
+ */
+ free_irq(port->irq, port);
++ if (port->mapbase == AT91RM9200_BASE_US0)
++ free_irq(AT91_PIN_PA19, port);
++ if (port->mapbase == AT91RM9200_BASE_US3)
++ free_irq(AT91_PIN_PA24, port);
+
+ /*
+ * If there is a specific "close" function (to unregister