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staging: comedi: pcl818: interrupt handlers should not busywait

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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 pcl818_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>
This commit is contained in:
H Hartley Sweeten 2014-03-04 11:29:33 -07:00 committed by Greg Kroah-Hartman
parent db0446d0e2
commit 127005717d
1 changed files with 7 additions and 12 deletions
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19
drivers/staging/comedi/drivers/pcl818.c
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@ -547,21 +547,16 @@ static irqreturn_t interrupt_pcl818_ai_mode13_int(int irq, void *d)
struct comedi_subdevice *s = dev->read_subdev;
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int chan;
int timeout = 50; /* wait max 50us */
while (timeout--) {
if (inb(dev->iobase + PCL818_STATUS) & 0x10)
goto conv_finish;
udelay(1);
if (pcl818_ai_eoc(dev, s, NULL, 0)) {
outb(0, dev->iobase + PCL818_STATUS); /* clear INT request */
comedi_error(dev, "A/D mode1/3 IRQ without DRDY!");
s->cancel(dev, s);
s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
comedi_event(dev, s);
return IRQ_HANDLED;
}
outb(0, dev->iobase + PCL818_STATUS); /* clear INT request */
comedi_error(dev, "A/D mode1/3 IRQ without DRDY!");
s->cancel(dev, s);
s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
comedi_event(dev, s);
return IRQ_HANDLED;
conv_finish:
comedi_buf_put(s->async, pcl818_ai_get_sample(dev, s, &chan));
outb(0, dev->iobase + PCL818_CLRINT); /* clear INT request */