isci: audit usage of BUG_ON macro in isci driver

Removes unnecessary usage of BUG_ON macro, excluding core directory.
In some cases macro is unnecesary, check is done in caller function.
In other cases macro is replaced by if construction with
appropriate warning.

Signed-off-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
[changed some survivable bug conditions to WARN_ONCE]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/core/scic_sds_request.c

@@ -1635,7 +1635,6 @@ static void scic_sds_request_completed_state_enter(
 	struct isci_host *ihost = sci_object_get_association(scic);
 	struct isci_request *ireq = sci_object_get_association(sci_req);
 
-
 	SET_STATE_HANDLER(sci_req,
 			  scic_sds_request_state_handler_table,
 			  SCI_BASE_REQUEST_STATE_COMPLETED);

drivers/scsi/isci/init.c

@@ -362,8 +362,6 @@ static int isci_setup_interrupts(struct pci_dev *pdev)
 		else
 			isr = isci_msix_isr;
 
-		BUG_ON(!isci_host);
-
 		err = devm_request_irq(&pdev->dev, msix->vector, isr, 0,
 				       DRV_NAME"-msix", isci_host);
 		if (!err)
@@ -379,13 +377,11 @@ static int isci_setup_interrupts(struct pci_dev *pdev)
 		pci_disable_msix(pdev);
 		goto intx;
 	}
-
 	return 0;
 
  intx:
 	err = devm_request_irq(&pdev->dev, pdev->irq, isci_intx_isr,
 			       IRQF_SHARED, DRV_NAME"-intx", pdev);
-
 	return err;
 }
 

drivers/scsi/isci/port.c

@@ -178,6 +178,7 @@ void isci_port_link_up(
 	unsigned long success = true;
 
 	BUG_ON(isci_phy->isci_port != NULL);
+
 	isci_phy->isci_port = isci_port;
 
 	dev_dbg(&isci_host->pdev->dev,

drivers/scsi/isci/remote_device.c

@@ -202,8 +202,6 @@ static enum sci_status isci_remote_device_construct(
 
 	sci_object_set_association(to_sci_dev(isci_device), isci_device);
 
-	BUG_ON(port->isci_host == NULL);
-
 	/* start the device. */
 	status = scic_remote_device_start(to_sci_dev(isci_device),
 					  ISCI_REMOTE_DEVICE_START_TIMEOUT);
@@ -257,8 +255,12 @@ isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport)
 		return NULL;
 	}
 
-	BUG_ON(!list_empty(&idev->reqs_in_process));
-	BUG_ON(!list_empty(&idev->node));
+	if (WARN_ONCE(!list_empty(&idev->reqs_in_process), "found requests in process\n"))
+		return NULL;
+
+	if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n"))
+		return NULL;
+
 	isci_remote_device_change_state(idev, isci_freed);
 
 	return idev;

drivers/scsi/isci/request.c

@@ -472,7 +472,6 @@ int isci_request_execute(
 
  out:
 	if (status != SCI_SUCCESS) {
-
 		/* release dma memory on failure. */
 		isci_request_free(isci_host, request);
 		request = NULL;

drivers/scsi/isci/request.h

@@ -193,8 +193,6 @@ static inline enum isci_request_status isci_request_change_started_to_newstate(
 	enum isci_request_status old_state;
 	unsigned long flags;
 
-	BUG_ON(isci_request == NULL);
-
 	spin_lock_irqsave(&isci_request->state_lock, flags);
 
 	old_state = isci_request->status;
@@ -243,7 +241,8 @@ static inline void isci_request_free(
 	struct isci_host *isci_host,
 	struct isci_request *isci_request)
 {
-	BUG_ON(isci_request == NULL);
+	if (!isci_request)
+		return;
 
 	/* release the dma memory if we fail. */
 	dma_pool_free(isci_host->dma_pool, isci_request,

drivers/scsi/isci/task.c

@@ -272,7 +272,7 @@ static enum sci_status isci_task_request_build(
 {
 	struct scic_sds_remote_device *sci_device;
 	enum sci_status status = SCI_FAILURE;
-	struct isci_request *request;
+	struct isci_request *request = NULL;
 	struct isci_remote_device *isci_device;
 /*	struct sci_sas_identify_address_frame_protocols dev_protocols; */
 	struct smp_discover_response_protocols dev_protocols;
@@ -372,8 +372,6 @@ static void isci_tmf_timeout_cb(void *tmf_request_arg)
 	struct isci_tmf *tmf = isci_request_access_tmf(request);
 	enum sci_status status;
 
-	BUG_ON(request->ttype != tmf_task);
-
 	/* This task management request has timed-out.  Terminate the request
 	 * so that the request eventually completes to the requestor in the
 	 * request completion callback path.
@@ -1121,8 +1119,11 @@ static void isci_abort_task_process_cb(
 		 * request state was already set to "aborted" by the abort
 		 * task function.
 		 */
-		BUG_ON((old_request->status != aborted)
-			&& (old_request->status != completed));
+		if ((old_request->status != aborted)
+			&& (old_request->status != completed))
+			dev_err(&old_request->isci_host->pdev->dev,
+				"%s: Bad request status (%d): tmf=%p, old_request=%p\n",
+				__func__, old_request->status, tmf, old_request);
 		break;
 
 	case isci_tmf_timed_out: