[SCSI] add SCSI_UNKNOWN and LUN transfer limit restrictions

Original From: Ingo Flaschberger <if@xip.at>

To support the RA4100 array from Compaq.

This patch now correctly handles SCSI_UNKNOWN types with regard to
BLIST_REPORTLUNS2 (allow it) and cdb[1] LUN inclusion (don't).

It also allows a BLIST_MAX_512 flag to restrict the maximum transfer
length to 512 blocks (apparently this is an RA4100 problem).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f14945996ede..1a5474bd11a1 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -673,6 +673,7 @@ static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
         case TYPE_MEDIUM_CHANGER:
         case TYPE_ENCLOSURE:
         case TYPE_COMM:
+        case TYPE_RAID:
         case TYPE_RBC:
                 sdev->writeable = 1;
                 break;
@@ -738,6 +739,13 @@ static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
                 sdev->select_no_atn = 1;
 
         /*
+         * Maximum 512 sector transfer length
+         * broken RA4x00 Compaq Disk Array
+         */
+        if (*bflags & BLIST_MAX_512)
+                blk_queue_max_sectors(sdev->request_queue, 512);
+
+        /*
          * Some devices may not want to have a start command automatically
          * issued when a device is added.
          */
@@ -1123,10 +1131,13 @@ static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
          * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
          * support more than 8 LUNs.
          */
-        if ((bflags & BLIST_NOREPORTLUN) || 
-             starget->scsi_level < SCSI_2 ||
-            (starget->scsi_level < SCSI_3 && 
-             (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) )
+        if (bflags & BLIST_NOREPORTLUN)
+                return 1;
+        if (starget->scsi_level < SCSI_2 &&
+            starget->scsi_level != SCSI_UNKNOWN)
+                return 1;
+        if (starget->scsi_level < SCSI_3 &&
+            (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
                 return 1;
         if (bflags & BLIST_NOLUN)
                 return 0;