[PATCH AUTOSEL 4.19 402/671] serial: stm32: fix a recursive locking in stm32_config_rs485

Sasha Levin
2020-01-16T18:52:39Z

From: Borut Seljak <borut.seljak@t-2.net>

[ Upstream commit 707aeea13a9c85520262e11899d86df3c4b48262 ]

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@t-2.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 1334e4293977..d096e552176c 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;
}
--
2.20.1