[PATCH 2/6] staging: comedi: dt2814: Don't wait for conversion in interrupt handler

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



When the interrupt handler decides the final sample has been acquired,
it turns off the timer enable (ENB) bit in the Command register.  That
triggers another A/D conversion.  The interrupt handler currently waits
for that to finish and then reads the resulting, unwanted sample.  Since
the functions for handling Comedi read instructions and for setting up
asynchronous commands now call `dt2814_ai_clear()` to wait for and
discard any spurious A/D conversion, let's remove that code from the
interrupt handler.

Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
 drivers/staging/comedi/drivers/dt2814.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/comedi/drivers/dt2814.c b/drivers/staging/comedi/drivers/dt2814.c
index 7e73aa094eea..8a70b7ba30f4 100644
--- a/drivers/staging/comedi/drivers/dt2814.c
+++ b/drivers/staging/comedi/drivers/dt2814.c
@@ -238,21 +238,13 @@ static irqreturn_t dt2814_interrupt(int irq, void *d)
 	inb(dev->iobase + DT2814_DATA);
 
 	if (!(--devpriv->ntrig)) {
-		int i;
-
 		outb(0, dev->iobase + DT2814_CSR);
 		/*
-		 * note: turning off timed mode triggers another
-		 * sample.
+		 * Note: turning off timed mode triggers another
+		 * sample.  This will be mopped up by the calls to
+		 * dt2814_ai_clear().
 		 */
 
-		for (i = 0; i < DT2814_TIMEOUT; i++) {
-			if (inb(dev->iobase + DT2814_CSR) & DT2814_FINISH)
-				break;
-		}
-		inb(dev->iobase + DT2814_DATA);
-		inb(dev->iobase + DT2814_DATA);
-
 		s->async->events |= COMEDI_CB_EOA;
 	}
 	comedi_handle_events(dev, s);
-- 
2.30.0

_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel



[Index of Archives]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux