diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 6e1d5f6f68a90477bd603b160f4fac0656f6eabc..f1ef63b9c75ceeb08ccf7badf5ff48bf4f6bf178 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;