[PATCH AUTOSEL 5.1 050/141] serial: uartps: Use the same dynamic major number for all ports

[Sasha Levin]

From: Shubhrajyoti Datta <shubhrajyoti.da...@xilinx.com>

[ Upstream commit ab262666018de6f4e206b021386b93ed0c164316 ]

Let kernel to find out major number dynamically for the first device and
then reuse it for other instances.
This fixes the issue that each uart is registered with a
different major number.

After the patch:
crw-------    1 root     root      253,   0 Jun 10 08:31 /dev/ttyPS0
crw--w----    1 root     root      253,   1 Jan  1  1970 /dev/ttyPS1

Fixes: 024ca329bfb9 ("serial: uartps: Register own uart console and driver 
structures")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.da...@xilinx.com>
Signed-off-by: Michal Simek <michal.si...@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/tty/serial/xilinx_uartps.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c 
b/drivers/tty/serial/xilinx_uartps.c
index 74089f5e5b53..fd0aa1e4e5ad 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -29,12 +29,12 @@
 
 #define CDNS_UART_TTY_NAME     "ttyPS"
 #define CDNS_UART_NAME         "xuartps"
-#define CDNS_UART_MAJOR                0       /* use dynamic node allocation 
*/
 #define CDNS_UART_FIFO_SIZE    64      /* FIFO size */
 #define CDNS_UART_REGISTER_SPACE       0x1000
 
 /* Rx Trigger level */
 static int rx_trigger_level = 56;
+static int uartps_major;
 module_param(rx_trigger_level, uint, S_IRUGO);
 MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
 
@@ -1507,7 +1507,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
        cdns_uart_uart_driver->owner = THIS_MODULE;
        cdns_uart_uart_driver->driver_name = driver_name;
        cdns_uart_uart_driver->dev_name = CDNS_UART_TTY_NAME;
-       cdns_uart_uart_driver->major = CDNS_UART_MAJOR;
+       cdns_uart_uart_driver->major = uartps_major;
        cdns_uart_uart_driver->minor = cdns_uart_data->id;
        cdns_uart_uart_driver->nr = 1;
 
@@ -1536,6 +1536,7 @@ 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;
 
        /*
-- 
2.20.1