staging: gpib: Set control lines in attach

When the driver is attached the state of the main control lines
is not defined and can lead to hangs. Set the control lines to
a known state (logic false).

Fixes: 4cd654f ("staging: gpib: Add gpio bitbang GPIB driver")
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20250418173434.2892-9-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: dpenkler

drivers/staging/gpib/gpio/gpib_bitbang.c

@@ -1262,6 +1262,10 @@ static int bb_attach(struct gpib_board *board, const struct gpib_board_config *c
 		gpiod_direction_output(TE, 1);
 		gpiod_direction_output(PE, 1);
 	}
+/* Set main control lines to a known state */
+	gpiod_direction_output(IFC, 1);
+	gpiod_direction_output(REN, 1);
+	gpiod_direction_output(_ATN, 1);
 
 	if (strcmp(PINMAP_2, pin_map) == 0) { /* YOGA: enable level shifters */
 		gpiod_direction_output(YOGA_ENABLE, 1);