staging: comedi: pcl812: interrupt handlers should not busywait

The interrupt is only generated by the hardware at the completion of
an A/D conversion. Because of this the sanity check to make sure that
the A/D conversion is complete and data is available is probably
unnecessary but it doesn't hurt anything.

The busywait loop is a different issue. Interrupt routines should not
busywait. That's just mean...

Remove the bustwait and use pcl812_ai_eoc() to check for the end-of-
conversion.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index d67df0aaf24124a4141034305828fe5d45d41e31..d84348d1d854779eb580518e7b28da4db134fe5f 100644 (file)
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -887,8 +887,6 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 {
-       char err = 1;
-       unsigned int timeout;
        struct comedi_device *dev = d;
        struct pcl812_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
@@ -897,26 +895,7 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 
        s->async->events = 0;
 
-       timeout = 50;           /* wait max 50us, it must finish under 33us */
-       if (s->maxdata > 0x0fff) {
-               while (timeout--) {
-                       if (!(inb(dev->iobase + ACL8216_STATUS) & ACL8216_DRDY)) {
-                               err = 0;
-                               break;
-                       }
-                       udelay(1);
-               }
-       } else {
-               while (timeout--) {
-                       if (!(inb(dev->iobase + PCL812_AD_HI) & PCL812_DRDY)) {
-                               err = 0;
-                               break;
-                       }
-                       udelay(1);
-               }
-       }
-
-       if (err) {
+       if (pcl812_ai_eoc(dev, s, NULL, 0)) {
                dev_dbg(dev->class_dev, "A/D cmd IRQ without DRDY!\n");
                s->cancel(dev, s);
                s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;