[PATCH] serial: uartps: Fix uartps_major handling

[PATCH] serial: uartps: Fix uartps_major handling

[Michal Simek]

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


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Re: [PATCH] serial: uartps: Fix uartps_major handling

[Greg Kroah-Hartman]

On Fri, Sep 13, 2019 at 09:28:29AM +0200, Michal Simek wrote:
> 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")

This is not a valid sha1 in Linus's tree :(

Please fix up and resend.

thanks,

greg k-h

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Re: [PATCH] serial: uartps: Fix uartps_major handling

[Michal Simek]

On 04. 10. 19 14:52, Greg Kroah-Hartman wrote:
> On Fri, Sep 13, 2019 at 09:28:29AM +0200, Michal Simek wrote:
>> 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")
> 
> This is not a valid sha1 in Linus's tree :(
> 
> Please fix up and resend.

grr. It is sha1 from stable tree. Will resend.

Thanks,
Michal



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