1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 1d176642e523..4d56d214fa05 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -1515,6 +1515,12 @@ struct dma_async_tx_descriptor *stedma40_memcpy_sg(struct dma_chan *chan,
                                              chan);
         unsigned long flags;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Unallocated channel.\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
         spin_lock_irqsave(&d40c->lock, flags);
         d40d = d40_desc_get(d40c);
 
@@ -1710,6 +1716,13 @@ static void d40_free_chan_resources(struct dma_chan *chan)
         int err;
         unsigned long flags;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Cannot free unallocated channel\n", __func__);
+                return;
+        }
+
+
         spin_lock_irqsave(&d40c->lock, flags);
 
         err = d40_free_dma(d40c);
@@ -1732,6 +1745,12 @@ static struct dma_async_tx_descriptor *d40_prep_memcpy(struct dma_chan *chan,
         unsigned long flags;
         int err = 0;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Channel is not allocated.\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
         spin_lock_irqsave(&d40c->lock, flags);
         d40d = d40_desc_get(d40c);
 
@@ -1947,6 +1966,12 @@ static struct dma_async_tx_descriptor *d40_prep_slave_sg(struct dma_chan *chan,
         unsigned long flags;
         int err;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Cannot prepare unallocated channel\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
         if (d40c->dma_cfg.pre_transfer)
                 d40c->dma_cfg.pre_transfer(chan,
                                            d40c->dma_cfg.pre_transfer_data,
@@ -1993,6 +2018,13 @@ static enum dma_status d40_tx_status(struct dma_chan *chan,
         dma_cookie_t last_complete;
         int ret;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Cannot read status of unallocated channel\n",
+                        __func__);
+                return -EINVAL;
+        }
+
         last_complete = d40c->completed;
         last_used = chan->cookie;
 
@@ -2012,6 +2044,12 @@ static void d40_issue_pending(struct dma_chan *chan)
         struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
         unsigned long flags;
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Channel is not allocated!\n", __func__);
+                return;
+        }
+
         spin_lock_irqsave(&d40c->lock, flags);
 
         /* Busy means that pending jobs are already being processed */
@@ -2027,6 +2065,12 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
         unsigned long flags;
         struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
 
+        if (d40c->phy_chan == NULL) {
+                dev_err(&d40c->chan.dev->device,
+                        "[%s] Channel is not allocated!\n", __func__);
+                return -EINVAL;
+        }
+
         switch (cmd) {
         case DMA_TERMINATE_ALL:
                 spin_lock_irqsave(&d40c->lock, flags);