From: Lukas Wunner <lukas@xxxxxxxxx> commit dc76697d7e933d5e299116f219c890568785ea15 upstream. Unbinding the bcm2835aux UART driver raises the following error if the maximum number of 8250 UARTs is set to 1 (via the 8250.nr_uarts module parameter or CONFIG_SERIAL_8250_RUNTIME_UARTS): (NULL device *): Removing wrong port: a6f80333 != fa20408b That's because bcm2835aux_serial_probe() retrieves UART line number 1 from the devicetree and stores it in data->uart.port.line, while serial8250_register_8250_port() instead uses UART line number 0, which is stored in data->line. On driver unbind, bcm2835aux_serial_remove() uses data->uart.port.line, which contains the wrong number. Fix it. The issue does not occur if the maximum number of 8250 UARTs is >= 2. Fixes: bdc5f3009580 ("serial: bcm2835: add driver for bcm2835-aux-uart") Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.6+ Cc: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx> Link: https://lore.kernel.org/r/912ccf553c5258135c6d7e8f404a101ef320f0f4.1579175223.git.lukas@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_bcm2835aux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_bcm2835aux.c +++ b/drivers/tty/serial/8250/8250_bcm2835aux.c @@ -119,7 +119,7 @@ static int bcm2835aux_serial_remove(stru { struct bcm2835aux_data *data = platform_get_drvdata(pdev); - serial8250_unregister_port(data->uart.port.line); + serial8250_unregister_port(data->line); clk_disable_unprepare(data->clk); return 0;