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-rw-r--r--drivers/scsi/hpsa.c39
1 files changed, 28 insertions, 11 deletions
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 6e1d5f6f68a9..f1ef63b9c75c 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -3674,7 +3674,7 @@ static int hpsa_scatter_gather(struct ctlr_info *h,
struct scsi_cmnd *cmd)
{
struct scatterlist *sg;
- int use_sg, i, sg_index, chained;
+ int use_sg, i, sg_limit, chained, last_sg;
struct SGDescriptor *curr_sg;
BUG_ON(scsi_sg_count(cmd) > h->maxsgentries);
@@ -3686,22 +3686,39 @@ static int hpsa_scatter_gather(struct ctlr_info *h,
if (!use_sg)
goto sglist_finished;
+ /*
+ * If the number of entries is greater than the max for a single list,
+ * then we have a chained list; we will set up all but one entry in the
+ * first list (the last entry is saved for link information);
+ * otherwise, we don't have a chained list and we'll set up at each of
+ * the entries in the one list.
+ */
curr_sg = cp->SG;
- chained = 0;
- sg_index = 0;
- scsi_for_each_sg(cmd, sg, use_sg, i) {
- if (i == h->max_cmd_sg_entries - 1 &&
- use_sg > h->max_cmd_sg_entries) {
- chained = 1;
- curr_sg = h->cmd_sg_list[cp->cmdindex];
- sg_index = 0;
- }
+ chained = use_sg > h->max_cmd_sg_entries;
+ sg_limit = chained ? h->max_cmd_sg_entries - 1 : use_sg;
+ last_sg = scsi_sg_count(cmd) - 1;
+ scsi_for_each_sg(cmd, sg, sg_limit, i) {
hpsa_set_sg_descriptor(curr_sg, sg);
curr_sg++;
}
+ if (chained) {
+ /*
+ * Continue with the chained list. Set curr_sg to the chained
+ * list. Modify the limit to the total count less the entries
+ * we've already set up. Resume the scan at the list entry
+ * where the previous loop left off.
+ */
+ curr_sg = h->cmd_sg_list[cp->cmdindex];
+ sg_limit = use_sg - sg_limit;
+ for_each_sg(sg, sg, sg_limit, i) {
+ hpsa_set_sg_descriptor(curr_sg, sg);
+ curr_sg++;
+ }
+ }
+
/* Back the pointer up to the last entry and mark it as "last". */
- (--curr_sg)->Ext = cpu_to_le32(HPSA_SG_LAST);
+ (curr_sg - 1)->Ext = cpu_to_le32(HPSA_SG_LAST);
if (use_sg + chained > h->maxSG)
h->maxSG = use_sg + chained;