/* STP tasks come from libata which has already mapped
         * the SG list */
-       if (task->task_proto == SAS_PROTOCOL_STP)
+       if (sas_protocol_ata(task->task_proto))
                num_sg = task->num_scatter;
        else
                num_sg = pci_map_sg(asd_ha->pcidev, task->scatter,
 
        return 0;
 err_unmap:
-       if (task->task_proto != SAS_PROTOCOL_STP)
+       if (sas_protocol_ata(task->task_proto))
                pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
                             task->data_dir);
        return res;
 
        task->total_xfer_len = size;
        task->data_dir = pci_dma_dir;
        task->task_done = sas_disc_task_done;
+       if (pci_dma_dir != PCI_DMA_NONE &&
+           sas_protocol_ata(task->task_proto)) {
+               task->num_scatter = pci_map_sg(task->dev->port->ha->pcidev,
+                                              task->scatter,
+                                              task->num_scatter,
+                                              task->data_dir);
+       }
 
        for (retries = 0; retries < 5; retries++) {
                task->task_state_flags = SAS_TASK_STATE_PENDING;
                }
        }
 ex_err:
-       if (pci_dma_dir != PCI_DMA_NONE)
+       if (pci_dma_dir != PCI_DMA_NONE) {
+               if (sas_protocol_ata(task->task_proto))
+                       pci_unmap_sg(task->dev->port->ha->pcidev,
+                                    task->scatter, task->num_scatter,
+                                    task->data_dir);
                kfree(scatter);
+       }
 out:
        return res;
 }
 
        SAS_PROTOCOL_SSP                = 0x08,
 };
 
+static inline int sas_protocol_ata(enum sas_protocol proto)
+{
+       return ((proto & SAS_PROTOCOL_SATA) ||
+               (proto & SAS_PROTOCOL_STP))? 1 : 0;
+}
+
 enum sas_linkrate {
        /* These Values are defined in the SAS standard */
        SAS_LINK_RATE_UNKNOWN = 0,