[PATCH 5/8] staging: comedi: addi_apci_2032: only disable triggered interrupts

Ian Abbott abbotti at mev.co.uk
Mon Dec 3 18:15:44 UTC 2012


The interrupt handler disables all interrupt sources when a valid
interrupt occurs.  Just disable the triggered interrupt source so we can
still get interrupts for the other interrupt source.

Also add a comment indicating why the triggered interrupt source is
disabled.  The interrupt sources are level-sensitive and indicate
hardware errors that are likely to be persistent, so if we reenabled
them they would just keep triggering repeatedly.

Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
 drivers/staging/comedi/drivers/addi_apci_2032.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/addi_apci_2032.c b/drivers/staging/comedi/drivers/addi_apci_2032.c
index 4c348dd..98691fd 100644
--- a/drivers/staging/comedi/drivers/addi_apci_2032.c
+++ b/drivers/staging/comedi/drivers/addi_apci_2032.c
@@ -246,7 +246,13 @@ static irqreturn_t apci2032_interrupt(int irq, void *d)
 		return IRQ_NONE;
 
 	val = inl(dev->iobase + APCI2032_INT_STATUS_REG) & 3;
-	outl(0x00, dev->iobase + APCI2032_INT_CTRL_REG);
+	/* Disable triggered interrupt sources. */
+	outl(~val & 3, dev->iobase + APCI2032_INT_CTRL_REG);
+	/*
+	 * Note: We don't reenable the triggered interrupt sources because they
+	 * are level-sensitive, hardware error status interrupt sources and
+	 * they'd keep triggering interrupts repeatedly.
+	 */
 
 	if (comedi_buf_put(s->async, val))
 		s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
-- 
1.8.0




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