diff --git a/drivers/staging/comedi/drivers/addi_apci_1564.c b/drivers/staging/comedi/drivers/addi_apci_1564.c
index 0141ed9592da..5924421bc949 100644
--- a/drivers/staging/comedi/drivers/addi_apci_1564.c
+++ b/drivers/staging/comedi/drivers/addi_apci_1564.c
@@ -58,48 +58,33 @@ static irqreturn_t apci1564_interrupt(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct apci1564_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
-	unsigned int ui_DO, ui_DI;
-	unsigned int ui_Timer;
-	unsigned int ui_C1, ui_C2, ui_C3, ui_C4;
-	unsigned int ul_Command2 = 0;
+	unsigned int status;
+	unsigned int ctrl;
+	unsigned int chan;
 
 	/* check interrupt is from this device */
 	if ((inl(devpriv->amcc_iobase + AMCC_OP_REG_INTCSR) &
 	     INTCSR_INTR_ASSERTED) == 0)
 		return IRQ_NONE;
 
-	/* check which interrupt was triggered */
-	ui_DI = inl(devpriv->amcc_iobase + APCI1564_DI_IRQ_REG) &
-		   APCI1564_DI_INT_ENABLE;
-	ui_DO = inl(devpriv->amcc_iobase + APCI1564_DO_IRQ_REG) & 0x01;
-	ui_Timer = inl(devpriv->amcc_iobase + APCI1564_TIMER_IRQ_REG) & 0x01;
-	ui_C1 =
-		inl(dev->iobase + APCI1564_TCW_IRQ_REG(APCI1564_COUNTER1)) & 0x1;
-	ui_C2 =
-		inl(dev->iobase + APCI1564_TCW_IRQ_REG(APCI1564_COUNTER2)) & 0x1;
-	ui_C3 =
-		inl(dev->iobase + APCI1564_TCW_IRQ_REG(APCI1564_COUNTER3)) & 0x1;
-	ui_C4 =
-		inl(dev->iobase + APCI1564_TCW_IRQ_REG(APCI1564_COUNTER4)) & 0x1;
-	if (ui_DI == 0 && ui_DO == 0 && ui_Timer == 0 && ui_C1 == 0
-		&& ui_C2 == 0 && ui_C3 == 0 && ui_C4 == 0) {
-		return IRQ_HANDLED;
-	}
-
-	if (ui_DI) {
+	status = inl(devpriv->amcc_iobase + APCI1564_DI_IRQ_REG);
+	if (status & APCI1564_DI_INT_ENABLE) {
 		/* disable the interrupt */
-		outl(ui_DI & APCI1564_DI_INT_DISABLE, devpriv->amcc_iobase + APCI1564_DI_IRQ_REG);
+		outl(status & APCI1564_DI_INT_DISABLE,
+		     devpriv->amcc_iobase + APCI1564_DI_IRQ_REG);
 
-		s->state = inl(dev->iobase + APCI1564_DI_INT_STATUS_REG) & 0xffff;
+		s->state = inl(dev->iobase + APCI1564_DI_INT_STATUS_REG)
+			       & 0xffff;
 		comedi_buf_put(s, s->state);
 		s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
 		comedi_event(dev, s);
 
 		/* enable the interrupt */
-		outl(ui_DI, devpriv->amcc_iobase + APCI1564_DI_IRQ_REG);
+		outl(status, devpriv->amcc_iobase + APCI1564_DI_IRQ_REG);
 	}
 
-	if (ui_DO == 1) {
+	status = inl(devpriv->amcc_iobase + APCI1564_DO_IRQ_REG);
+	if (status & 0x01) {
 		/* Check for Digital Output interrupt Type */
 		/* 1: VCC interrupt			   */
 		/* 2: CC interrupt			   */
@@ -112,98 +97,34 @@ static irqreturn_t apci1564_interrupt(int irq, void *d)
 		send_sig(SIGIO, devpriv->tsk_current, 0);
 	}
 
-	if (ui_Timer == 1) {
-		devpriv->timer_select_mode = ADDIDATA_TIMER;
-		if (devpriv->timer_select_mode) {
+	status = inl(devpriv->amcc_iobase + APCI1564_TIMER_IRQ_REG);
+	if (status & 0x01) {
+		/*  Disable Timer Interrupt */
+		ctrl = inl(devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
+		outl(0x0, devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
 
-			/*  Disable Timer Interrupt */
-			ul_Command2 = inl(devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
-			outl(0x0, devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
+		/* Send a signal to from kernel to user space */
+		send_sig(SIGIO, devpriv->tsk_current, 0);
 
-			/* Send a signal to from kernel to user space */
-			send_sig(SIGIO, devpriv->tsk_current, 0);
-
-			/*  Enable Timer Interrupt */
-
-			outl(ul_Command2, devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
-		}
+		/*  Enable Timer Interrupt */
+		outl(ctrl, devpriv->amcc_iobase + APCI1564_TIMER_CTRL_REG);
 	}
 
-	if (ui_C1 == 1) {
-		devpriv->timer_select_mode = ADDIDATA_COUNTER;
-		if (devpriv->timer_select_mode) {
-
+	for (chan = 0; chan < 4; chan++) {
+		status = inl(dev->iobase + APCI1564_TCW_IRQ_REG(chan));
+		if (status & 0x01) {
 			/*  Disable Counter Interrupt */
-			ul_Command2 =
-				inl(dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER1));
-			outl(0x0,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER1));
+			ctrl = inl(dev->iobase + APCI1564_TCW_CTRL_REG(chan));
+			outl(0x0, dev->iobase + APCI1564_TCW_CTRL_REG(chan));
 
 			/* Send a signal to from kernel to user space */
 			send_sig(SIGIO, devpriv->tsk_current, 0);
 
 			/*  Enable Counter Interrupt */
-			outl(ul_Command2,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER1));
+			outl(ctrl, dev->iobase + APCI1564_TCW_CTRL_REG(chan));
 		}
 	}
 
-	if (ui_C2 == 1) {
-		devpriv->timer_select_mode = ADDIDATA_COUNTER;
-		if (devpriv->timer_select_mode) {
-
-			/*  Disable Counter Interrupt */
-			ul_Command2 =
-				inl(dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER2));
-			outl(0x0,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER2));
-
-			/* Send a signal to from kernel to user space */
-			send_sig(SIGIO, devpriv->tsk_current, 0);
-
-			/*  Enable Counter Interrupt */
-			outl(ul_Command2,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER2));
-		}
-	}
-
-	if (ui_C3 == 1) {
-		devpriv->timer_select_mode = ADDIDATA_COUNTER;
-		if (devpriv->timer_select_mode) {
-
-			/*  Disable Counter Interrupt */
-			ul_Command2 =
-				inl(dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER3));
-			outl(0x0,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER3));
-
-			/* Send a signal to from kernel to user space */
-			send_sig(SIGIO, devpriv->tsk_current, 0);
-
-			/*  Enable Counter Interrupt */
-			outl(ul_Command2,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER3));
-		}
-	}
-
-	if (ui_C4 == 1) {
-		devpriv->timer_select_mode = ADDIDATA_COUNTER;
-		if (devpriv->timer_select_mode) {
-
-			/*  Disable Counter Interrupt */
-			ul_Command2 =
-				inl(dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER4));
-			outl(0x0,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER4));
-
-			/* Send a signal to from kernel to user space */
-			send_sig(SIGIO, devpriv->tsk_current, 0);
-
-			/*  Enable Counter Interrupt */
-			outl(ul_Command2,
-			     dev->iobase + APCI1564_TCW_CTRL_REG(APCI1564_COUNTER4));
-		}
-	}
 	return IRQ_HANDLED;
 }