 if (dev_id == NULL) return IRQ_NONE; 
static irqreturn_t siu_interrupt(int irq, void *dev_id, struct pt_regs *regs){	struct uart_port *port;	uint8_t iir, lsr;	if (dev_id == NULL)		return IRQ_NONE;	port = (struct uart_port *)dev_id;	iir = siu_read(port, UART_IIR);	if (iir & UART_IIR_NO_INT)		return IRQ_NONE;	lsr = siu_read(port, UART_LSR);	if (lsr & UART_LSR_DR)		receive_chars(port, &lsr, regs);	check_modem_status(port);	if (lsr & UART_LSR_THRE)		transmit_chars(port);	return IRQ_HANDLED;}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/eae936e21bd726f9d9555f2262d439fbcd61dccf/vr41xx_siu.c/buggy/drivers/serial/vr41xx_siu.c