The atmel_complete_tx_dma() function disables IRQs at the start of the function by calling spin_lock_irqsave(&port->lock, flags); There is no need to disable them a second time using the spin_lock_irq() function and, in fact, doing so is a bug because it will enable IRQs prematurely when we call spin_unlock_irq(). Just use spin_lock/unlock() instead without disabling or enabling IRQs. Fixes: 08f738be88bb ("serial: at91: add tx dma support") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- drivers/tty/serial/atmel_serial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 6e9192f122aa..3467a875641a 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -868,11 +868,11 @@ static void atmel_complete_tx_dma(void *arg) dmaengine_terminate_all(chan); uart_xmit_advance(port, atmel_port->tx_len); - spin_lock_irq(&atmel_port->lock_tx); + spin_lock(&atmel_port->lock_tx); async_tx_ack(atmel_port->desc_tx); atmel_port->cookie_tx = -EINVAL; atmel_port->desc_tx = NULL; - spin_unlock_irq(&atmel_port->lock_tx); + spin_unlock(&atmel_port->lock_tx); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); -- 2.39.2