Patch "tty: serial: meson: if no alias specified use an available id" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    tty: serial: meson: if no alias specified use an available id

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tty-serial-meson-if-no-alias-specified-use-an-availa.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e7e14b757462fb9ba63ff16201863d50f76b7041
Author: Loys Ollivier <lollivier@xxxxxxxxxxxx>
Date:   Mon Jan 14 17:54:26 2019 +0100

    tty: serial: meson: if no alias specified use an available id
    
    [ Upstream commit a26988e8fef4b258d1b771e0f4b2e3b67cb2e044 ]
    
    At probe, the uart driver tries to get an id from a device tree alias.
    When no alias was specified, the driver would return an error and probing
    would fail.
    
    Providing an alias for registering a serial device should not be mandatory.
    If the device tree does not specify an alias, provide an id from a reserved
    range so that the probing can continue.
    
    Suggested-by: Rob Herring <robh@xxxxxxxxxx>
    Signed-off-by: Loys Ollivier <lollivier@xxxxxxxxxxxx>
    Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Stable-dep-of: 2a1d728f20ed ("tty: serial: meson: fix hard LOCKUP on crtscts mode")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 1838d0be37044..849ce8c1ef392 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -72,7 +72,8 @@
 #define AML_UART_BAUD_USE		BIT(23)
 #define AML_UART_BAUD_XTAL		BIT(24)
 
-#define AML_UART_PORT_NUM		6
+#define AML_UART_PORT_NUM		12
+#define AML_UART_PORT_OFFSET		6
 #define AML_UART_DEV_NAME		"ttyAML"
 
 
@@ -667,10 +668,20 @@ static int meson_uart_probe(struct platform_device *pdev)
 	struct resource *res_mem, *res_irq;
 	struct uart_port *port;
 	int ret = 0;
+	int id = -1;
 
 	if (pdev->dev.of_node)
 		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
 
+	if (pdev->id < 0) {
+		for (id = AML_UART_PORT_OFFSET; id < AML_UART_PORT_NUM; id++) {
+			if (!meson_ports[id]) {
+				pdev->id = id;
+				break;
+			}
+		}
+	}
+
 	if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM)
 		return -EINVAL;