target/linux/layerscape/patches-5.4/819-uart-0007-MLK-15094-tty-serial-fsl_lpuart-check-dma_tx_in_prog.patch

   1 From 31a4e41820cdaad9d4c151beefe5ab0698f4865a Mon Sep 17 00:00:00 2001
   2 From: Fugang Duan <fugang.duan@nxp.com>
   3 Date: Thu, 15 Jun 2017 16:48:31 +0800
   4 Subject: [PATCH] MLK-15094 tty: serial: fsl_lpuart: check dma_tx_in_progress
   5  in callback
   6
   7 There have a corner case that tx DMA .callback() is coming after
   8 .flush_buffer(), then .callback() should check dma_tx_in_progress
   9 flag and return in directly.
  10
  11 Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
  12 Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
  13 ---
  14  drivers/tty/serial/fsl_lpuart.c | 4 ++++
  15  1 file changed, 4 insertions(+)
  16
  17 --- a/drivers/tty/serial/fsl_lpuart.c
  18 +++ b/drivers/tty/serial/fsl_lpuart.c
  19 @@ -490,6 +490,10 @@ static void lpuart_dma_tx_complete(void
  20         unsigned long flags;
  21
  22         spin_lock_irqsave(&sport->port.lock, flags);
  23 +       if (!sport->dma_tx_in_progress) {
  24 +               spin_unlock_irqrestore(&sport->port.lock, flags);
  25 +               return;
  26 +       }
  27
  28         dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
  29