static irqreturn_t pcie_isr(int irq, void *dev_id)
{
        struct test_device *ctrl = data;
        u32 status;
…

        status = readl(ctrl->reg + INT_STATUS);
        /*
         * Check to see if it was our interrupt
         */
        if (!(status & 0x000C))
                return IRQ_NONE;

        /* Clear the interrupt */
        writel(status, ctrl->reg + INT_STATUS);

        if (status & 0x0004) {
                /*
                 * Tx interrupt pending.
                 */
                 ....
       }

        if (status & 0x0008) {
                /* Rx interrupt Pending */
                /* The system freezes if I read again the INT_STATUS register as given below */
                status = readl(ctrl->reg + INT_STATUS);
                ....
        }
..
        return IRQ_HANDLED;
}