[PATCH 4.9 085/102] staging: comedi: ni_mio_common: ack ai fifo error interrupts.

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Frank Mori Hess <fmh6jj@xxxxxxxxx>

commit e1d9fc04c41840a4688ef6ce90b6dcca157ea4d7 upstream.

Ack ai fifo error interrupts in interrupt handler to clear interrupt
after fifo overflow.  It should prevent lock-ups after the ai fifo
overflows.

Cc: <stable@xxxxxxxxxxxxxxx> # v4.2+
Signed-off-by: Frank Mori Hess <fmh6jj@xxxxxxxxx>
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/staging/comedi/drivers/ni_mio_common.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -1284,6 +1284,8 @@ static void ack_a_interrupt(struct comed
 		ack |= NISTC_INTA_ACK_AI_START;
 	if (a_status & NISTC_AI_STATUS1_STOP)
 		ack |= NISTC_INTA_ACK_AI_STOP;
+	if (a_status & NISTC_AI_STATUS1_OVER)
+		ack |= NISTC_INTA_ACK_AI_ERR;
 	if (ack)
 		ni_stc_writew(dev, ack, NISTC_INTA_ACK_REG);
 }