dw_dmac: check for mapping errors

Otherwise we get a warning in case of CONFIG_DMA_API_DEBUG=y

[   45.775943] WARNING: at lib/dma-debug.c:933 check_unmap+0x5d6/0x6ac()
[   45.782369] dw_dmac dw_dmac.0: DMA-API: device driver failed to check map error[device address=0x00000000356efcc0] [size=28 bytes] [mapped as single]

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 14 insertions, 6 deletions

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index c0c9370ddd3f..dd7a8192d5a0 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1087,6 +1087,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
         struct dw_desc          *desc;
         int                     i;
         unsigned long           flags;
+        int                     ret;
 
         dev_vdbg(chan2dev(chan), "%s\n", __func__);
 
@@ -1110,12 +1111,8 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
                 spin_unlock_irqrestore(&dwc->lock, flags);
 
                 desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
-                if (!desc) {
-                        dev_info(chan2dev(chan),
-                                "only allocated %d descriptors\n", i);
-                        spin_lock_irqsave(&dwc->lock, flags);
-                        break;
-                }
+                if (!desc)
+                        goto err_desc_alloc;
 
                 INIT_LIST_HEAD(&desc->tx_list);
                 dma_async_tx_descriptor_init(&desc->txd, chan);
@@ -1123,6 +1120,10 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
                 desc->txd.flags = DMA_CTRL_ACK;
                 desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
                                 sizeof(desc->lli), DMA_TO_DEVICE);
+                ret = dma_mapping_error(chan2parent(chan), desc->txd.phys);
+                if (ret)
+                        goto err_desc_alloc;
+
                 dwc_desc_put(dwc, desc);
 
                 spin_lock_irqsave(&dwc->lock, flags);
@@ -1134,6 +1135,13 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
         dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
 
         return i;
+
+err_desc_alloc:
+        kfree(desc);
+
+        dev_info(chan2dev(chan), "only allocated %d descriptors\n", i);
+
+        return i;
 }
 
 static void dwc_free_chan_resources(struct dma_chan *chan)