From 31a4e41820cdaad9d4c151beefe5ab0698f4865a Mon Sep 17 00:00:00 2001 From: Fugang Duan Date: Thu, 15 Jun 2017 16:48:31 +0800 Subject: [PATCH] MLK-15094 tty: serial: fsl_lpuart: check dma_tx_in_progress in callback 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 Signed-off-by: Vipul Kumar --- drivers/tty/serial/fsl_lpuart.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -490,6 +490,10 @@ static void lpuart_dma_tx_complete(void 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(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);