DIF fixes

@@ -378,7 +378,7 @@ static int sd_prep_fn(struct request_que
 	sector_t threshold;
 	unsigned int this_count = rq->nr_sectors;
 	unsigned int timeout = sdp->timeout;
-	int ret;
+	int ret, host_dif;
 
 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);

@@ -509,7 +509,8 @@ static int sd_prep_fn(struct request_que
 					rq->nr_sectors));
 
 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
-	if (scsi_host_dif_capable(sdp->host, sdkp->protection_type))
+	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
+	if (host_dif)
 		SCpnt->cmnd[1] = 1 << 5;
 	else
 		SCpnt->cmnd[1] = 0;

@@ -567,7 +568,7 @@ static int sd_prep_fn(struct request_que
 	SCpnt->sdb.length = this_count * sdp->sector_size;
 
 	/* If DIF or DIX is enabled, tell HBA how to handle request */
-	if (sdkp->protection_type || scsi_prot_sg_count(SCpnt))
+	if (host_dif || scsi_prot_sg_count(SCpnt))
 		sd_dif_op(SCpnt, sdkp->protection_type, scsi_prot_sg_count(SCpnt));
 
 	/*

@@ -1248,14 +1248,12 @@ void sd_read_protection_type(struct scsi
 	else
 		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
 
+	sdkp->protection_type = type;
+
 	switch (type) {
 	case SD_DIF_TYPE0_PROTECTION:
-		sdkp->protection_type = 0;
-		break;
-
 	case SD_DIF_TYPE1_PROTECTION:
 	case SD_DIF_TYPE3_PROTECTION:
-		sdkp->protection_type = type;
 		break;
 
 	case SD_DIF_TYPE2_PROTECTION:

@@ -1273,7 +1271,6 @@ void sd_read_protection_type(struct scsi
 	return;
 
 disable:
-	sdkp->protection_type = 0;
 	sdkp->capacity = 0;
 }
 

@@ -321,7 +321,6 @@ void sd_dif_config_host(struct scsi_disk
 		if (scsi_host_dif_capable(sdp->host, type) == 0) {
 			sd_printk(KERN_INFO, sdkp, "Type %d protection " \
 				  "unsupported by HBA. Disabling DIF.\n", type);
-			sdkp->protection_type = 0;
 			return;
 		}
 

@@ -569,7 +569,8 @@ static int sd_prep_fn(struct request_que
 
 	/* If DIF or DIX is enabled, tell HBA how to handle request */
 	if (host_dif || scsi_prot_sg_count(SCpnt))
-		sd_dif_op(SCpnt, sdkp->protection_type, scsi_prot_sg_count(SCpnt));
+		sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
+			  sdkp->protection_type);
 
 	/*
 	 * We shouldn't disconnect in the middle of a sector, so with a dumb

@@ -99,7 +99,7 @@ struct sd_dif_tuple {
 
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
-extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int);
+extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int, unsigned int);
 extern void sd_dif_config_host(struct scsi_disk *);
 extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
 extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);

@@ -311,24 +311,26 @@ void sd_dif_config_host(struct scsi_disk
 	struct scsi_device *sdp = sdkp->device;
 	struct gendisk *disk = sdkp->disk;
 	u8 type = sdkp->protection_type;
+	int dif, dix;
 
-	/* If this HBA doesn't support DIX, resort to normal I/O or DIF */
-	if (scsi_host_dix_capable(sdp->host, type) == 0) {
+	dif = scsi_host_dif_capable(sdp->host, type);
+	dix = scsi_host_dix_capable(sdp->host, type);
 
-		if (type == SD_DIF_TYPE0_PROTECTION)
-			return;
+	if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
+		dif = 0; dix = 1;
+	}
 
-		if (scsi_host_dif_capable(sdp->host, type) == 0) {
-			sd_printk(KERN_INFO, sdkp, "Type %d protection " \
-				  "unsupported by HBA. Disabling DIF.\n", type);
-			return;
-		}
+	if (type) {
+		if (dif)
+			sd_printk(KERN_INFO, sdkp,
+				  "Enabling DIF Type %d protection\n", type);
+		else
+			sd_printk(KERN_INFO, sdkp,
+				  "Disabling DIF Type %d protection\n", type);
+	}
 
-		sd_printk(KERN_INFO, sdkp, "Enabling DIF Type %d protection\n",
-			  type);
-
+	if (!dix)
 		return;
-	}
 
 	/* Enable DMA of protection information */
 	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)

@@ -343,10 +345,10 @@ void sd_dif_config_host(struct scsi_disk
 			blk_integrity_register(disk, &dif_type1_integrity_crc);
 
 	sd_printk(KERN_INFO, sdkp,
-		  "Enabling %s integrity protection\n", disk->integrity->name);
+		  "Enabling DIX %s protection\n", disk->integrity->name);
 
 	/* Signal to block layer that we support sector tagging */
-	if (type && sdkp->ATO) {
+	if (dif && type && sdkp->ATO) {
 		if (type == SD_DIF_TYPE3_PROTECTION)
 			disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
 		else

@@ -360,7 +362,7 @@ void sd_dif_config_host(struct scsi_disk
 /*
  * DIF DMA operation magic decoder ring.
  */
-void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix)
+void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix, unsigned int type)
 {
 	int csum_convert, prot_op;
 

@@ -405,7 +407,8 @@ void sd_dif_op(struct scsi_cmnd *scmd, u
 	}
 
 	scsi_set_prot_op(scmd, prot_op);
-	scsi_set_prot_type(scmd, dif);
+	if (dif)
+		scsi_set_prot_type(scmd, type);
 }
 
 /*