dmaengine: remove BUG_ON while registering devices

DMAengine core has BUG_ON to check for mandatory operations and ones based
on capabilities, but they use BUG_ON, so remove and move to error returns
and logging the errors gracefully

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dmaengine.c

@@ -923,28 +923,85 @@ int dma_async_device_register(struct dma_device *device)
 		return -ENODEV;
 
 	/* validate device routines */
-	BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
-		!device->device_prep_dma_memcpy);
-	BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
-		!device->device_prep_dma_xor);
-	BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
-		!device->device_prep_dma_xor_val);
-	BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
-		!device->device_prep_dma_pq);
-	BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
-		!device->device_prep_dma_pq_val);
-	BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
-		!device->device_prep_dma_memset);
-	BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
-		!device->device_prep_dma_interrupt);
-	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
-		!device->device_prep_dma_cyclic);
-	BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
-		!device->device_prep_interleaved_dma);
+	if (!device->dev) {
+		pr_err("DMAdevice must have dev\n");
+		return -EIO;
+	}
 
-	BUG_ON(!device->device_tx_status);
-	BUG_ON(!device->device_issue_pending);
-	BUG_ON(!device->dev);
+	if (dma_has_cap(DMA_MEMCPY, device->cap_mask) && !device->device_prep_dma_memcpy) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_MEMCPY");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_XOR, device->cap_mask) && !device->device_prep_dma_xor) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_XOR");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_XOR_VAL, device->cap_mask) && !device->device_prep_dma_xor_val) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_XOR_VAL");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_PQ, device->cap_mask) && !device->device_prep_dma_pq) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_PQ");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_PQ_VAL, device->cap_mask) && !device->device_prep_dma_pq_val) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_PQ_VAL");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_MEMSET, device->cap_mask) && !device->device_prep_dma_memset) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_MEMSET");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_INTERRUPT");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_CYCLIC, device->cap_mask) && !device->device_prep_dma_cyclic) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_CYCLIC");
+		return -EIO;
+	}
+
+	if (dma_has_cap(DMA_INTERLEAVE, device->cap_mask) && !device->device_prep_interleaved_dma) {
+		dev_err(device->dev,
+			"Device claims capability %s, but op is not defined\n",
+			"DMA_INTERLEAVE");
+		return -EIO;
+	}
+
+
+	if (!device->device_tx_status) {
+		dev_err(device->dev, "Device tx_status is not defined\n");
+		return -EIO;
+	}
+
+
+	if (!device->device_issue_pending) {
+		dev_err(device->dev, "Device issue_pending is not defined\n");
+		return -EIO;
+	}
 
 	/* note: this only matters in the
 	 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case