[PATCH] serial: uartps: Fix uartps_major handling

Michal Simek
2019-09-13T07:28:35Z

There are two parts which should be fixed. The first one is to assigned
uartps_major at the end of probe() to avoid complicated logic when
something fails.
The second part is initialized uartps_major number to 0 when last device is
removed. This will ensure that on next probe driver will ask for new
dynamic major number.

Fixes: c9712e333809 ("serial: uartps: Use the same dynamic major number for all ports")
Reported-by: Paul Thomas <pthomas8589@gmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

drivers/tty/serial/xilinx_uartps.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index f145946f659b..92df0c4f1c7a 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1550,7 +1550,6 @@ static int cdns_uart_probe(struct platform_device *pdev)
goto err_out_id;
}

- uartps_major = cdns_uart_uart_driver->tty_driver->major;
cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;

/*
@@ -1680,6 +1679,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
console_port = NULL;
#endif

+ uartps_major = cdns_uart_uart_driver->tty_driver->major;
cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
"cts-override");
return 0;
@@ -1741,6 +1741,12 @@ static int cdns_uart_remove(struct platform_device *pdev)
console_port = NULL;
#endif

+ /* If this is last instance major number should be initialized */
+ mutex_lock(&bitmap_lock);
+ if (bitmap_empty(bitmap, MAX_UART_INSTANCES))
+ uartps_major = 0;
+ mutex_unlock(&bitmap_lock);
+
uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
return rc;
}
--
2.17.1