diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 7600639..add419d 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -149,7 +149,6 @@ static int twa_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset);
 static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg);
 static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int request_id);
 static char *twa_string_lookup(twa_message_type *table, unsigned int aen_code);
-static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id);
 
 /* Functions */
 
@@ -1340,11 +1339,11 @@ static irqreturn_t twa_interrupt(int irq, void *dev_instance)
 				}
 
 				/* Now complete the io */
+				scsi_dma_unmap(cmd);
+				cmd->scsi_done(cmd);
 				tw_dev->state[request_id] = TW_S_COMPLETED;
 				twa_free_request_id(tw_dev, request_id);
 				tw_dev->posted_request_count--;
-				tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-				twa_unmap_scsi_data(tw_dev, request_id);
 			}
 
 			/* Check for valid status after each drain */
@@ -1402,26 +1401,6 @@ static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
 	}
 } /* End twa_load_sgl() */
 
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twa_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
-	int use_sg;
-	struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-	use_sg = scsi_dma_map(cmd);
-	if (!use_sg)
-		return 0;
-	else if (use_sg < 0) {
-		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1c, "Failed to map scatter gather list");
-		return 0;
-	}
-
-	cmd->SCp.phase = TW_PHASE_SGLIST;
-	cmd->SCp.have_data_in = use_sg;
-
-	return use_sg;
-} /* End twa_map_scsi_sg_data() */
-
 /* This function will poll for a response interrupt of a request */
 static int twa_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds)
 {
@@ -1600,9 +1579,11 @@ static int twa_reset_device_extension(TW_Device_Extension *tw_dev)
 		    (tw_dev->state[i] != TW_S_INITIAL) &&
 		    (tw_dev->state[i] != TW_S_COMPLETED)) {
 			if (tw_dev->srb[i]) {
-				tw_dev->srb[i]->result = (DID_RESET << 16);
-				tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-				twa_unmap_scsi_data(tw_dev, i);
+				struct scsi_cmnd *cmd = tw_dev->srb[i];
+
+				cmd->result = (DID_RESET << 16);
+				scsi_dma_unmap(cmd);
+				cmd->scsi_done(cmd);
 			}
 		}
 	}
@@ -1781,21 +1762,18 @@ static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
 	/* Save the scsi command for use by the ISR */
 	tw_dev->srb[request_id] = SCpnt;
 
-	/* Initialize phase to zero */
-	SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
 	retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
 	switch (retval) {
 	case SCSI_MLQUEUE_HOST_BUSY:
+		scsi_dma_unmap(SCpnt);
 		twa_free_request_id(tw_dev, request_id);
-		twa_unmap_scsi_data(tw_dev, request_id);
 		break;
 	case 1:
-		tw_dev->state[request_id] = TW_S_COMPLETED;
-		twa_free_request_id(tw_dev, request_id);
-		twa_unmap_scsi_data(tw_dev, request_id);
 		SCpnt->result = (DID_ERROR << 16);
+		scsi_dma_unmap(SCpnt);
 		done(SCpnt);
+		tw_dev->state[request_id] = TW_S_COMPLETED;
+		twa_free_request_id(tw_dev, request_id);
 		retval = 0;
 	}
 out:
@@ -1863,8 +1841,8 @@ static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
 				command_packet->sg_list[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
 				command_packet->sg_list[0].length = cpu_to_le32(TW_MIN_SGL_LENGTH);
 			} else {
-				sg_count = twa_map_scsi_sg_data(tw_dev, request_id);
-				if (sg_count == 0)
+				sg_count = scsi_dma_map(srb);
+				if (sg_count < 0)
 					goto out;
 
 				scsi_for_each_sg(srb, sg, sg_count, i) {
@@ -1979,15 +1957,6 @@ static char *twa_string_lookup(twa_message_type *table, unsigned int code)
 	return(table[index].text);
 } /* End twa_string_lookup() */
 
-/* This function will perform a pci-dma unmap */
-static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
-	struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-	if (cmd->SCp.phase == TW_PHASE_SGLIST)
-		scsi_dma_unmap(cmd);
-} /* End twa_unmap_scsi_data() */
-
 /* This function gets called when a disk is coming on-line */
 static int twa_slave_configure(struct scsi_device *sdev)
 {
diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h
index 040f721..0fdc83c 100644
--- a/drivers/scsi/3w-9xxx.h
+++ b/drivers/scsi/3w-9xxx.h
@@ -324,11 +324,6 @@ static twa_message_type twa_error_table[] = {
 #define TW_CURRENT_DRIVER_BUILD 0
 #define TW_CURRENT_DRIVER_BRANCH 0
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SINGLE  1
-#define TW_PHASE_SGLIST  2
-
 /* Misc defines */
 #define TW_9550SX_DRAIN_COMPLETED	      0xFFFF
 #define TW_SECTOR_SIZE                        512
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 2361772..f837485 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -290,26 +290,6 @@ static int twl_post_command_packet(TW_Device_Extension *tw_dev, int request_id)
 	return 0;
 } /* End twl_post_command_packet() */
 
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twl_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
-	int use_sg;
-	struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-	use_sg = scsi_dma_map(cmd);
-	if (!use_sg)
-		return 0;
-	else if (use_sg < 0) {
-		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1, "Failed to map scatter gather list");
-		return 0;
-	}
-
-	cmd->SCp.phase = TW_PHASE_SGLIST;
-	cmd->SCp.have_data_in = use_sg;
-
-	return use_sg;
-} /* End twl_map_scsi_sg_data() */
-
 /* This function hands scsi cdb's to the firmware */
 static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry_ISO *sglistarg)
 {
@@ -357,8 +337,8 @@ static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
 	if (!sglistarg) {
 		/* Map sglist from scsi layer to cmd packet */
 		if (scsi_sg_count(srb)) {
-			sg_count = twl_map_scsi_sg_data(tw_dev, request_id);
-			if (sg_count == 0)
+			sg_count = scsi_dma_map(srb);
+			if (sg_count <= 0)
 				goto out;
 
 			scsi_for_each_sg(srb, sg, sg_count, i) {
@@ -1102,15 +1082,6 @@ out:
 	return retval;
 } /* End twl_initialize_device_extension() */
 
-/* This function will perform a pci-dma unmap */
-static void twl_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
-	struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
-	if (cmd->SCp.phase == TW_PHASE_SGLIST)
-		scsi_dma_unmap(cmd);
-} /* End twl_unmap_scsi_data() */
-
 /* This function will handle attention interrupts */
 static int twl_handle_attention_interrupt(TW_Device_Extension *tw_dev)
 {
@@ -1251,11 +1222,11 @@ static irqreturn_t twl_interrupt(int irq, void *dev_instance)
 			}
 
 			/* Now complete the io */
+			scsi_dma_unmap(cmd);
+			cmd->scsi_done(cmd);
 			tw_dev->state[request_id] = TW_S_COMPLETED;
 			twl_free_request_id(tw_dev, request_id);
 			tw_dev->posted_request_count--;
-			tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-			twl_unmap_scsi_data(tw_dev, request_id);
 		}
 
 		/* Check for another response interrupt */
@@ -1400,10 +1371,12 @@ static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_res
 		if ((tw_dev->state[i] != TW_S_FINISHED) &&
 		    (tw_dev->state[i] != TW_S_INITIAL) &&
 		    (tw_dev->state[i] != TW_S_COMPLETED)) {
-			if (tw_dev->srb[i]) {
-				tw_dev->srb[i]->result = (DID_RESET << 16);
-				tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-				twl_unmap_scsi_data(tw_dev, i);
+			struct scsi_cmnd *cmd = tw_dev->srb[i];
+
+			if (cmd) {
+				cmd->result = (DID_RESET << 16);
+				scsi_dma_unmap(cmd);
+				cmd->scsi_done(cmd);
 			}
 		}
 	}
@@ -1507,9 +1480,6 @@ static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
 	/* Save the scsi command for use by the ISR */
 	tw_dev->srb[request_id] = SCpnt;
 
-	/* Initialize phase to zero */
-	SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
 	retval = twl_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
 	if (retval) {
 		tw_dev->state[request_id] = TW_S_COMPLETED;
diff --git a/drivers/scsi/3w-sas.h b/drivers/scsi/3w-sas.h
index d474892..fec6449 100644
--- a/drivers/scsi/3w-sas.h
+++ b/drivers/scsi/3w-sas.h
@@ -103,10 +103,6 @@ static char *twl_aen_severity_table[] =
 #define TW_CURRENT_DRIVER_BUILD 0
 #define TW_CURRENT_DRIVER_BRANCH 0
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SGLIST  2
-
 /* Misc defines */
 #define TW_SECTOR_SIZE                        512
 #define TW_MAX_UNITS			      32
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index c75f204..2940bd7 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -1271,32 +1271,6 @@ static int tw_initialize_device_extension(TW_Device_Extension *tw_dev)
 	return 0;
 } /* End tw_initialize_device_extension() */
 
-static int tw_map_scsi_sg_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
-{
-	int use_sg;
-
-	dprintk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data()\n");
-
-	use_sg = scsi_dma_map(cmd);
-	if (use_sg < 0) {
-		printk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data(): pci_map_sg() failed.\n");
-		return 0;
-	}
-
-	cmd->SCp.phase = TW_PHASE_SGLIST;
-	cmd->SCp.have_data_in = use_sg;
-
-	return use_sg;
-} /* End tw_map_scsi_sg_data() */
-
-static void tw_unmap_scsi_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
-{
-	dprintk(KERN_WARNING "3w-xxxx: tw_unmap_scsi_data()\n");
-
-	if (cmd->SCp.phase == TW_PHASE_SGLIST)
-		scsi_dma_unmap(cmd);
-} /* End tw_unmap_scsi_data() */
-
 /* This function will reset a device extension */
 static int tw_reset_device_extension(TW_Device_Extension *tw_dev)
 {
@@ -1319,8 +1293,8 @@ static int tw_reset_device_extension(TW_Device_Extension *tw_dev)
 			srb = tw_dev->srb[i];
 			if (srb != NULL) {
 				srb->result = (DID_RESET << 16);
-				tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
-				tw_unmap_scsi_data(tw_dev->tw_pci_dev, tw_dev->srb[i]);
+				scsi_dma_unmap(srb);
+				srb->scsi_done(srb);
 			}
 		}
 	}
@@ -1767,8 +1741,8 @@ static int tw_scsiop_read_write(TW_Device_Extension *tw_dev, int request_id)
 	command_packet->byte8.io.lba = lba;
 	command_packet->byte6.block_count = num_sectors;
 
-	use_sg = tw_map_scsi_sg_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
-	if (!use_sg)
+	use_sg = scsi_dma_map(srb);
+	if (use_sg <= 0)
 		return 1;
 
 	scsi_for_each_sg(tw_dev->srb[request_id], sg, use_sg, i) {
@@ -1955,9 +1929,6 @@ static int tw_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_c
 	/* Save the scsi command for use by the ISR */
 	tw_dev->srb[request_id] = SCpnt;
 
-	/* Initialize phase to zero */
-	SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
 	switch (*command) {
 		case READ_10:
 		case READ_6:
@@ -2185,12 +2156,11 @@ static irqreturn_t tw_interrupt(int irq, void *dev_instance)
 
 				/* Now complete the io */
 				if ((error != TW_ISR_DONT_COMPLETE)) {
+					scsi_dma_unmap(tw_dev->srb[request_id]);
+					tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
 					tw_dev->state[request_id] = TW_S_COMPLETED;
 					tw_state_request_finish(tw_dev, request_id);
 					tw_dev->posted_request_count--;
-					tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
-					
-					tw_unmap_scsi_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
 				}
 			}
 				
diff --git a/drivers/scsi/3w-xxxx.h b/drivers/scsi/3w-xxxx.h
index 29b0b84e..6f65e66 100644
--- a/drivers/scsi/3w-xxxx.h
+++ b/drivers/scsi/3w-xxxx.h
@@ -195,11 +195,6 @@ static unsigned char tw_sense_table[][4] =
 #define TW_AEN_SMART_FAIL        0x000F
 #define TW_AEN_SBUF_FAIL         0x0024
 
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SINGLE 1
-#define TW_PHASE_SGLIST 2
-
 /* Misc defines */
 #define TW_ALIGNMENT_6000		      64 /* 64 bytes */
 #define TW_ALIGNMENT_7000                     4  /* 4 bytes */
diff --git a/drivers/scsi/aha1542.c b/drivers/scsi/aha1542.c
index ec43276..b95d277 100644
--- a/drivers/scsi/aha1542.c
+++ b/drivers/scsi/aha1542.c
@@ -375,9 +375,10 @@ static int aha1542_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 	u8 lun = cmd->device->lun;
 	unsigned long flags;
 	int bufflen = scsi_bufflen(cmd);
-	int mbo;
+	int mbo, sg_count;
 	struct mailbox *mb = aha1542->mb;
 	struct ccb *ccb = aha1542->ccb;
+	struct chain *cptr;
 
 	if (*cmd->cmnd == REQUEST_SENSE) {
 		/* Don't do the command - we have the sense data already */
@@ -397,6 +398,13 @@ static int aha1542_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 		print_hex_dump_bytes("command: ", DUMP_PREFIX_NONE, cmd->cmnd, cmd->cmd_len);
 	}
 #endif
+	if (bufflen) {	/* allocate memory before taking host_lock */
+		sg_count = scsi_sg_count(cmd);
+		cptr = kmalloc(sizeof(*cptr) * sg_count, GFP_KERNEL | GFP_DMA);
+		if (!cptr)
+			return SCSI_MLQUEUE_HOST_BUSY;
+	}
+
 	/* Use the outgoing mailboxes in a round-robin fashion, because this
 	   is how the host adapter will scan for them */
 
@@ -441,19 +449,10 @@ static int aha1542_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 
 	if (bufflen) {
 		struct scatterlist *sg;
-		struct chain *cptr;
-		int i, sg_count = scsi_sg_count(cmd);
+		int i;
 
 		ccb[mbo].op = 2;	/* SCSI Initiator Command  w/scatter-gather */
-		cmd->host_scribble = kmalloc(sizeof(*cptr)*sg_count,
-		                                         GFP_KERNEL | GFP_DMA);
-		cptr = (struct chain *) cmd->host_scribble;
-		if (cptr == NULL) {
-			/* free the claimed mailbox slot */
-			aha1542->int_cmds[mbo] = NULL;
-			spin_unlock_irqrestore(sh->host_lock, flags);
-			return SCSI_MLQUEUE_HOST_BUSY;
-		}
+		cmd->host_scribble = (void *)cptr;
 		scsi_for_each_sg(cmd, sg, sg_count, i) {
 			any2scsi(cptr[i].dataptr, isa_page_to_bus(sg_page(sg))
 								+ sg->offset);
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index 262ab83..9f77d23 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -226,6 +226,7 @@ static struct {
 	{"PIONEER", "CD-ROM DRM-624X", NULL, BLIST_FORCELUN | BLIST_SINGLELUN},
 	{"Promise", "VTrak E610f", NULL, BLIST_SPARSELUN | BLIST_NO_RSOC},
 	{"Promise", "", NULL, BLIST_SPARSELUN},
+	{"QNAP", "iSCSI Storage", NULL, BLIST_MAX_1024},
 	{"QUANTUM", "XP34301", "1071", BLIST_NOTQ},
 	{"REGAL", "CDC-4X", NULL, BLIST_MAX5LUN | BLIST_SINGLELUN},
 	{"SanDisk", "ImageMate CF-SD1", NULL, BLIST_FORCELUN},
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 60aae01..6efab1c 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -897,6 +897,12 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	 */
 	if (*bflags & BLIST_MAX_512)
 		blk_queue_max_hw_sectors(sdev->request_queue, 512);
+	/*
+	 * Max 1024 sector transfer length for targets that report incorrect
+	 * max/optimal lengths and relied on the old block layer safe default
+	 */
+	else if (*bflags & BLIST_MAX_1024)
+		blk_queue_max_hw_sectors(sdev->request_queue, 1024);
 
 	/*
 	 * Some devices may not want to have a start command automatically
diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
index 183eaab..96e3f56 100644
--- a/include/scsi/scsi_devinfo.h
+++ b/include/scsi/scsi_devinfo.h
@@ -36,5 +36,6 @@
 					     for sequential scan */
 #define BLIST_TRY_VPD_PAGES	0x10000000 /* Attempt to read VPD pages */
 #define BLIST_NO_RSOC		0x20000000 /* don't try to issue RSOC */
+#define BLIST_MAX_1024		0x40000000 /* maximum 1024 sector cdb length */
 
 #endif
