target/linux/ipq806x/patches-3.18/152-dmaengine-Make-channel-allocation-callbacks-optional.patch

   1 From c4b54a648e682f678c338619df848233a6babc46 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime.ripard@free-electrons.com>
   3 Date: Mon, 17 Nov 2014 14:41:59 +0100
   4 Subject: [PATCH] dmaengine: Make channel allocation callbacks optional
   5
   6 Nowadays, some drivers don't have anything in there channel allocation
   7 callbacks anymore.
   8
   9 Remove the BUG_ON if those callbacks aren't implemented, in order to allow
  10 drivers to not implement them.
  11
  12 Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
  13 Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  14 Signed-off-by: Vinod Koul <vinod.koul@intel.com>
  15 ---
  16  drivers/dma/dmaengine.c | 18 +++++++++++-------
  17  1 file changed, 11 insertions(+), 7 deletions(-)
  18
  19 --- a/drivers/dma/dmaengine.c
  20 +++ b/drivers/dma/dmaengine.c
  21 @@ -235,9 +235,11 @@ static int dma_chan_get(struct dma_chan
  22                 return -ENODEV;
  23
  24         /* allocate upon first client reference */
  25 -       ret = chan->device->device_alloc_chan_resources(chan);
  26 -       if (ret < 0)
  27 -               goto err_out;
  28 +       if (chan->device->device_alloc_chan_resources) {
  29 +               ret = chan->device->device_alloc_chan_resources(chan);
  30 +               if (ret < 0)
  31 +                       goto err_out;
  32 +       }
  33
  34         if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
  35                 balance_ref_count(chan);
  36 @@ -259,11 +261,15 @@ err_out:
  37   */
  38  static void dma_chan_put(struct dma_chan *chan)
  39  {
  40 +       /* This channel is not in use, bail out */
  41         if (!chan->client_count)
  42 -               return; /* this channel failed alloc_chan_resources */
  43 +               return;
  44 +
  45         chan->client_count--;
  46         module_put(dma_chan_to_owner(chan));
  47 -       if (chan->client_count == 0)
  48 +
  49 +       /* This channel is not in use anymore, free it */
  50 +       if (!chan->client_count && chan->device->device_free_chan_resources)
  51                 chan->device->device_free_chan_resources(chan);
  52  }
  53
  54 @@ -817,8 +823,6 @@ int dma_async_device_register(struct dma
  55         BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
  56                 !device->device_prep_interleaved_dma);
  57
  58 -       BUG_ON(!device->device_alloc_chan_resources);
  59 -       BUG_ON(!device->device_free_chan_resources);
  60         BUG_ON(!device->device_tx_status);
  61         BUG_ON(!device->device_issue_pending);
  62         BUG_ON(!device->dev);