[PATCH 14/66] staging: comedi: pcl818: interrupt handlers should not busywait
H Hartley Sweeten
hsweeten at visionengravers.com
Fri Feb 28 23:24:03 UTC 2014
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 at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcl818.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl818.c b/drivers/staging/comedi/drivers/pcl818.c
index 661a907..0167d7e 100644
--- a/drivers/staging/comedi/drivers/pcl818.c
+++ b/drivers/staging/comedi/drivers/pcl818.c
@@ -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 */
--
1.8.5.2
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