[PATCH 5.11 155/601] serial: stm32: call stm32_transmit_chars locked

Greg Kroah-Hartman
2021-05-12T17:07:35Z

From: Erwan Le Ray <erwan.leray@foss.st.com>

[ Upstream commit f16b90c2d9db3e6ac719d1946b9d335ca4ab33f3 ]

stm32_transmit_chars should be called under lock also in tx DMA callback.

Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20210304162308.8984-10-erwan.leray@foss.st.com
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 insertions(+)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index c2d87a8a8fe5..a6295897c537 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -290,13 +290,16 @@ static void stm32_usart_tx_dma_complete(void *arg)
struct uart_port *port = arg;
struct stm32_port *stm32port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
+ unsigned long flags;

dmaengine_terminate_async(stm32port->tx_ch);
stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
stm32port->tx_dma_busy = false;

/* Let's see if we have pending data to send */
+ spin_lock_irqsave(&port->lock, flags);
stm32_usart_transmit_chars(port);
+ spin_unlock_irqrestore(&port->lock, flags);
}

static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
--
2.30.2