From: Fugang Duan <fugang.duan@xxxxxxx> There have a corner case that tx DMA .callback() is coming after .flush_buffer(), then .callback() should check dma_tx_in_progress flag and return in directly. Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx> Signed-off-by: Vipul Kumar <vipul_kumar@xxxxxxxxxx> Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> --- drivers/tty/serial/fsl_lpuart.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 460e428b7592..117e011aff5f 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -479,6 +479,10 @@ static void lpuart_dma_tx_complete(void *arg) unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); + if (!sport->dma_tx_in_progress) { + spin_unlock_irqrestore(&sport->port.lock, flags); + return; + } dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); -- 2.17.1