staging: gpib: Fix sending clear and trigger events

This driver was not sending device clear or trigger events when the
board entered the DCAS or DTAS state respectively in device mode.

DCAS is the Device Clear Active State which is entered on receiving a
selective device clear message (SDC) or universal device clear message
(DCL) from the controller in charge.

DTAS is the Device Trigger Active State which is entered on receiving
a group execute trigger (GET) message from the controller.

In order for an application, implementing a particular device, to
detect when one of these states is entered the driver needs to send
the appropriate event.

Send the appropriate gpib_event when DCAS or DTAS is set in the
reported status word. This sets the DCAS or DTAS bits in the board's
status word which can be monitored by the application.

Fixes: 4e127de ("staging: gpib: Add National Instruments USB GPIB driver")
Cc: stable <[email protected]>
Tested-by: Dave Penkler <[email protected]>
Signed-off-by: Dave Penkler <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: dpenkler

drivers/staging/gpib/ni_usb/ni_usb_gpib.c

@@ -327,7 +327,10 @@ static void ni_usb_soft_update_status(struct gpib_board *board, unsigned int ni_
 	board->status &= ~clear_mask;
 	board->status &= ~ni_usb_ibsta_mask;
 	board->status |= ni_usb_ibsta & ni_usb_ibsta_mask;
-	// FIXME should generate events on DTAS and DCAS
+	if (ni_usb_ibsta & DCAS)
+		push_gpib_event(board, EVENT_DEV_CLR);
+	if (ni_usb_ibsta & DTAS)
+		push_gpib_event(board, EVENT_DEV_TRG);
 
 	spin_lock_irqsave(&board->spinlock, flags);
 /* remove set status bits from monitored set why ?***/