[SCSI] lpfc 8.3.39: Fix driver issues with large s/g lists for BlockGuard

Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index ad5b0f94a98d..3b10aa5745b5 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -4073,16 +4073,23 @@ MODULE_PARM_DESC(lpfc_delay_discovery,
 
 /*
  * lpfc_sg_seg_cnt - Initial Maximum DMA Segment Count
- * This value can be set to values between 64 and 256. The default value is
+ * This value can be set to values between 64 and 4096. The default value is
  * 64, but may be increased to allow for larger Max I/O sizes. The scsi layer
  * will be allowed to request I/Os of sizes up to (MAX_SEG_COUNT * SEG_SIZE).
+ * Because of the additional overhead involved in setting up T10-DIF,
+ * this parameter will be limited to 128 if BlockGuard is enabled under SLI4
+ * and will be limited to 512 if BlockGuard is enabled under SLI3.
  */
 LPFC_ATTR_R(sg_seg_cnt, LPFC_DEFAULT_SG_SEG_CNT, LPFC_DEFAULT_SG_SEG_CNT,
             LPFC_MAX_SG_SEG_CNT, "Max Scatter Gather Segment Count");
 
-LPFC_ATTR_R(prot_sg_seg_cnt, LPFC_DEFAULT_PROT_SG_SEG_CNT,
-                LPFC_DEFAULT_PROT_SG_SEG_CNT, LPFC_MAX_PROT_SG_SEG_CNT,
-                "Max Protection Scatter Gather Segment Count");
+/*
+ * This parameter will be depricated, the driver cannot limit the
+ * protection data s/g list.
+ */
+LPFC_ATTR_R(prot_sg_seg_cnt, LPFC_DEFAULT_SG_SEG_CNT,
+            LPFC_DEFAULT_SG_SEG_CNT, LPFC_MAX_SG_SEG_CNT,
+            "Max Protection Scatter Gather Segment Count");
 
 struct device_attribute *lpfc_hba_attrs[] = {
         &dev_attr_bg_info,