Re: [PATCH v3] serial: stm32: fix a recursive locking in stm32_config_rs485

From: Erwan LE RAY
Date: Thu Jun 06 2019 - 11:52:34 EST



On 6/6/19 12:19 PM, Borut Seljak wrote:
> Remove spin_lock_irqsave in stm32_config_rs485, it cause recursive locking.
> Already locked in uart_set_rs485_config.
>
> fixes: 1bcda09d291081 ("serial: stm32: add support for RS485 hardware control mode")
>
> Signed-off-by: Borut Seljak <borut.seljak@xxxxxxx>

Hi Borut,

Thanks for your patch.

Acked-by: Erwan Le Ray <erwan.leray@xxxxxx>

Please correct a typo in commit message: "Fixes" instead "fixes"

Erwan.

> ---
> drivers/tty/serial/stm32-usart.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
> index e8d7a7bb4339..5d072ec61071 100644
> --- a/drivers/tty/serial/stm32-usart.c
> +++ b/drivers/tty/serial/stm32-usart.c
> @@ -105,9 +105,7 @@ static int stm32_config_rs485(struct uart_port *port,
> struct stm32_usart_config *cfg = &stm32_port->info->cfg;
> u32 usartdiv, baud, cr1, cr3;
> bool over8;
> - unsigned long flags;
>
> - spin_lock_irqsave(&port->lock, flags);
> stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
>
> port->rs485 = *rs485conf;
> @@ -147,7 +145,6 @@ static int stm32_config_rs485(struct uart_port *port,
> }
>
> stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
> - spin_unlock_irqrestore(&port->lock, flags);
>
> return 0;
> }