1 files changed, 19 insertions, 15 deletions

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 5ad0ec1f0e29..97199b3c25a2 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -130,26 +130,14 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 static void dwc_initialize(struct dw_dma_chan *dwc)
 {
         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
-        struct dw_dma_slave *dws = dwc->chan.private;
         u32 cfghi = DWC_CFGH_FIFO_MODE;
         u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 
         if (dwc->initialized == true)
                 return;
 
-        if (dws) {
-                /*
-                 * We need controller-specific data to set up slave
-                 * transfers.
-                 */
-                BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
-
-                cfghi |= DWC_CFGH_DST_PER(dws->dst_id);
-                cfghi |= DWC_CFGH_SRC_PER(dws->src_id);
-        } else {
-                cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
-                cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
-        }
+        cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
+        cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
 
         channel_writel(dwc, CFG_LO, cfglo);
         channel_writel(dwc, CFG_HI, cfghi);
@@ -941,7 +929,7 @@ bool dw_dma_filter(struct dma_chan *chan, void *param)
         struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
         struct dw_dma_slave *dws = param;
 
-        if (!dws || dws->dma_dev != chan->device->dev)
+        if (dws->dma_dev != chan->device->dev)
                 return false;
 
         /* We have to copy data since dws can be temporary storage */
@@ -1165,6 +1153,14 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
          * doesn't mean what you think it means), and status writeback.
          */
 
+        /*
+         * We need controller-specific data to set up slave transfers.
+         */
+        if (chan->private && !dw_dma_filter(chan, chan->private)) {
+                dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
+                return -EINVAL;
+        }
+
         /* Enable controller here if needed */
         if (!dw->in_use)
                 dw_dma_on(dw);
@@ -1226,6 +1222,14 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
         spin_lock_irqsave(&dwc->lock, flags);
         list_splice_init(&dwc->free_list, &list);
         dwc->descs_allocated = 0;
+
+        /* Clear custom channel configuration */
+        dwc->src_id = 0;
+        dwc->dst_id = 0;
+
+        dwc->src_master = 0;
+        dwc->dst_master = 0;
+
         dwc->initialized = false;
 
         /* Disable interrupts */