queue-4.9/dmaengine-sh-rcar-dmac-with-cyclic-dma-residue-0-is-valid.patch

   1 From 907bd68a2edc491849e2fdcfe52c4596627bca94 Mon Sep 17 00:00:00 2001
   2 From: Dirk Behme <dirk.behme@de.bosch.com>
   3 Date: Fri, 12 Apr 2019 07:29:13 +0200
   4 Subject: dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid
   5
   6 From: Dirk Behme <dirk.behme@de.bosch.com>
   7
   8 commit 907bd68a2edc491849e2fdcfe52c4596627bca94 upstream.
   9
  10 Having a cyclic DMA, a residue 0 is not an indication of a completed
  11 DMA. In case of cyclic DMA make sure that dma_set_residue() is called
  12 and with this a residue of 0 is forwarded correctly to the caller.
  13
  14 Fixes: 3544d2878817 ("dmaengine: rcar-dmac: use result of updated get_residue in tx_status")
  15 Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
  16 Signed-off-by: Achim Dahlhoff <Achim.Dahlhoff@de.bosch.com>
  17 Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
  18 Signed-off-by: Yao Lihua <ylhuajnu@outlook.com>
  19 Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
  20 Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  21 Cc: <stable@vger.kernel.org> # v4.8+
  22 Signed-off-by: Vinod Koul <vkoul@kernel.org>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24
  25 ---
  26  drivers/dma/sh/rcar-dmac.c |    4 +++-
  27  1 file changed, 3 insertions(+), 1 deletion(-)
  28
  29 --- a/drivers/dma/sh/rcar-dmac.c
  30 +++ b/drivers/dma/sh/rcar-dmac.c
  31 @@ -1311,6 +1311,7 @@ static enum dma_status rcar_dmac_tx_stat
  32         enum dma_status status;
  33         unsigned long flags;
  34         unsigned int residue;
  35 +       bool cyclic;
  36
  37         status = dma_cookie_status(chan, cookie, txstate);
  38         if (status == DMA_COMPLETE || !txstate)
  39 @@ -1318,10 +1319,11 @@ static enum dma_status rcar_dmac_tx_stat
  40
  41         spin_lock_irqsave(&rchan->lock, flags);
  42         residue = rcar_dmac_chan_get_residue(rchan, cookie);
  43 +       cyclic = rchan->desc.running ? rchan->desc.running->cyclic : false;
  44         spin_unlock_irqrestore(&rchan->lock, flags);
  45
  46         /* if there's no residue, the cookie is complete */
  47 -       if (!residue)
  48 +       if (!residue && !cyclic)
  49                 return DMA_COMPLETE;
  50
  51         dma_set_residue(txstate, residue);