platform/x86: serdev_helpers: Check for serial_ctrl_uid == NULL

dell_uart_bl_pdev_probe() calls get_serdev_controller() with the
serial_ctrl_uid parameter set to NULL.

In case of errors this NULL parameter then gets passed to pr_err()
as argument matching a "%s" conversion specification. This leads to
compiler warnings when building with "make W=1".

Check serial_ctrl_uid before passing it to pr_err() to avoid these.

Fixes: dc5afd720f84 ("platform/x86: Add new get_serdev_controller() helper")
Cc: [email protected]
Suggested-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/platform/x86/serdev_helpers.h b/drivers/platform/x86/serdev_helpers.h
index bcf3a0c356ea..3bc7fd8e1e19 100644
--- a/drivers/platform/x86/serdev_helpers.h
+++ b/drivers/platform/x86/serdev_helpers.h
@@ -35,7 +35,7 @@ get_serdev_controller(const char *serial_ctrl_hid,
 	ctrl_adev = acpi_dev_get_first_match_dev(serial_ctrl_hid, serial_ctrl_uid, -1);
 	if (!ctrl_adev) {
 		pr_err("error could not get %s/%s serial-ctrl adev\n",
-		       serial_ctrl_hid, serial_ctrl_uid);
+		       serial_ctrl_hid, serial_ctrl_uid ?: "*");
 		return ERR_PTR(-ENODEV);
 	}
 
@@ -43,7 +43,7 @@ get_serdev_controller(const char *serial_ctrl_hid,
 	ctrl_dev = get_device(acpi_get_first_physical_node(ctrl_adev));
 	if (!ctrl_dev) {
 		pr_err("error could not get %s/%s serial-ctrl physical node\n",
-		       serial_ctrl_hid, serial_ctrl_uid);
+		       serial_ctrl_hid, serial_ctrl_uid ?: "*");
 		ctrl_dev = ERR_PTR(-ENODEV);
 		goto put_ctrl_adev;
 	}