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>

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index c0c9370ddd3ff8b0ee596daa551a53d040b75994..dd7a8192d5a0ecaf793ee314c025504ffcb11ea3 100644 (file)
--- 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);
@@ -1133,6 +1134,13 @@ 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;
 }