[PATCH v2 3/3] serial: 8250: skip platform device registration with no runtime ports

["Martin Hundebøll" <martin@geanix.com>]

Skip registration of the platform device used for built-in ports, if no
such ports are configured/created.

Signed-off-by: Martin Hundebøll <martin@geanix.com>
---

Change since v1:
 * call serial8250_pnp_init() also when nr_uarts is zero

 drivers/tty/serial/8250/8250_core.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index ba48431ec6e2..f4a08fb74c31 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1186,6 +1186,14 @@ static int __init serial8250_init(void)
 	if (ret)
 		goto unreg_uart_drv;
 
+	if (nr_uarts == 0) {
+		ret = platform_driver_register(&serial8250_isa_driver);
+		if (ret)
+			goto unreg_pnp;
+
+		goto out;
+	}
+
 	serial8250_isa_devs = platform_device_alloc("serial8250",
 						    PLAT8250_DEV_LEGACY);
 	if (!serial8250_isa_devs) {
@@ -1230,7 +1238,9 @@ static void __exit serial8250_exit(void)
 	serial8250_isa_devs = NULL;
 
 	platform_driver_unregister(&serial8250_isa_driver);
-	platform_device_unregister(isa_dev);
+
+	if (nr_uarts)
+		platform_device_unregister(isa_dev);
 
 	serial8250_pnp_exit();
 
-- 
2.38.0