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: 4cd654f84769 ("staging: gpib: Add gpio bitbang GPIB driver")
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
---
drivers/staging/gpib/gpio/gpib_bitbang.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/staging/gpib/gpio/gpib_bitbang.c b/drivers/staging/gpib/gpio/gpib_bitbang.c
index 5c134cfb6d61..625fef24a0bf 100644
--- a/drivers/staging/gpib/gpio/gpib_bitbang.c
+++ b/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);
--
2.49.0