gpiolib: don't bail out if get_direction() fails in gpiochip_add_data()

Since commit 9d846b1 ("gpiolib: check the return value of
gpio_chip::get_direction()") we check the return value of the
get_direction() callback as per its API contract. Some drivers have been
observed to fail to register now as they may call get_direction() in
gpiochip_add_data() in contexts where it has always silently failed.
Until we audit all drivers, replace the bail-out to a kernel log
warning.

Fixes: 9d846b1 ("gpiolib: check the return value of gpio_chip::get_direction()")
Reported-by: Mark Brown <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Reported-by: Marek Szyprowski <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Tested-by: Mark Brown <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
Tested-by: Marek Szyprowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>

drivers/gpio/gpiolib.c

@@ -1059,7 +1059,15 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 		if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
 			ret = gc->get_direction(gc, desc_index);
 			if (ret < 0)
-				goto err_cleanup_desc_srcu;
+				/*
+				 * FIXME: Bail-out here once all GPIO drivers
+				 * are updated to not return errors in
+				 * situations that can be considered normal
+				 * operation.
+				 */
+				dev_warn(&gdev->dev,
+					 "%s: get_direction failed: %d\n",
+					 __func__, ret);
 
 			assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
 		} else {