queue-4.4/dmaengine-at_xdmac-remove-bug_on-macro-in-tasklet.patch

   1 From 5fab0292dd849574f4383d04616dd3486cf9a59d Mon Sep 17 00:00:00 2001
   2 From: Nicolas Ferre <nicolas.ferre@microchip.com>
   3 Date: Wed, 3 Apr 2019 12:23:57 +0200
   4 Subject: dmaengine: at_xdmac: remove BUG_ON macro in tasklet
   5
   6 [ Upstream commit e2c114c06da2d9ffad5b16690abf008d6696f689 ]
   7
   8 Even if this case shouldn't happen when controller is properly programmed,
   9 it's still better to avoid dumping a kernel Oops for this.
  10 As the sequence may happen only for debugging purposes, log the error and
  11 just finish the tasklet call.
  12
  13 Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
  14 Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
  15 Signed-off-by: Vinod Koul <vkoul@kernel.org>
  16 Signed-off-by: Sasha Levin <sashal@kernel.org>
  17 ---
  18  drivers/dma/at_xdmac.c | 6 +++++-
  19  1 file changed, 5 insertions(+), 1 deletion(-)
  20
  21 diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
  22 index af24c5bf32d69..8aa3ccf42e55a 100644
  23 --- a/drivers/dma/at_xdmac.c
  24 +++ b/drivers/dma/at_xdmac.c
  25 @@ -1608,7 +1608,11 @@ static void at_xdmac_tasklet(unsigned long data)
  26                                         struct at_xdmac_desc,
  27                                         xfer_node);
  28                 dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
  29 -               BUG_ON(!desc->active_xfer);
  30 +               if (!desc->active_xfer) {
  31 +                       dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
  32 +                       spin_unlock_bh(&atchan->lock);
  33 +                       return;
  34 +               }
  35
  36                 txd = &desc->tx_dma_desc;
  37
  38 --
  39 2.20.1
  40