[SCSI] qla2xxx: Properly handle UNDERRUN completion statuses.

Correct issues where the lower scsi-status would be improperly
cleared, instead, allow the midlayer to process the status after
the proper residual-count checks are performed.  Finally,
validate firmware status flags prior to assigning values from the
FCP_RSP frame.

Signed-off-by: Lalit Chandivade <lalit.chandivade@qlogic.com>
Signed-off-by: Michael Hernandez <michael.hernandez@qlogic.com>
Signed-off-by: Ravi Anand <ravi.anand@qlogic.com>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 4d758d2..8049873 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1353,16 +1353,22 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct rsp_que *rsp, void *pkt)
 
        sense_len = rsp_info_len = resid_len = fw_resid_len = 0;
        if (IS_FWI2_CAPABLE(ha)) {
-               sense_len = le32_to_cpu(sts24->sense_len);
-               rsp_info_len = le32_to_cpu(sts24->rsp_data_len);
-               resid_len = le32_to_cpu(sts24->rsp_residual_count);
-               fw_resid_len = le32_to_cpu(sts24->residual_len);
+               if (scsi_status & SS_SENSE_LEN_VALID)
+                       sense_len = le32_to_cpu(sts24->sense_len);
+               if (scsi_status & SS_RESPONSE_INFO_LEN_VALID)
+                       rsp_info_len = le32_to_cpu(sts24->rsp_data_len);
+               if (scsi_status & (SS_RESIDUAL_UNDER | SS_RESIDUAL_OVER))
+                       resid_len = le32_to_cpu(sts24->rsp_residual_count);
+               if (comp_status == CS_DATA_UNDERRUN)
+                       fw_resid_len = le32_to_cpu(sts24->residual_len);
                rsp_info = sts24->data;
                sense_data = sts24->data;
                host_to_fcp_swap(sts24->data, sizeof(sts24->data));
        } else {
-               sense_len = le16_to_cpu(sts->req_sense_length);
-               rsp_info_len = le16_to_cpu(sts->rsp_info_len);
+               if (scsi_status & SS_SENSE_LEN_VALID)
+                       sense_len = le16_to_cpu(sts->req_sense_length);
+               if (scsi_status & SS_RESPONSE_INFO_LEN_VALID)
+                       rsp_info_len = le16_to_cpu(sts->rsp_info_len);
                resid_len = le32_to_cpu(sts->residual_length);
                rsp_info = sts->rsp_info;
                sense_data = sts->req_sense_data;
@@ -1449,38 +1455,62 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct rsp_que *rsp, void *pkt)
                break;
 
        case CS_DATA_UNDERRUN:
-               resid = resid_len;
+               DEBUG2(printk(KERN_INFO
+                   "scsi(%ld:%d:%d) UNDERRUN status detected 0x%x-0x%x. "
+                   "resid=0x%x fw_resid=0x%x cdb=0x%x os_underflow=0x%x\n",
+                   vha->host_no, cp->device->id, cp->device->lun, comp_status,
+                   scsi_status, resid_len, fw_resid_len, cp->cmnd[0],
+                   cp->underflow));
+
                /* Use F/W calculated residual length. */
-               if (IS_FWI2_CAPABLE(ha)) {
-                       if (!(scsi_status & SS_RESIDUAL_UNDER)) {
-                               lscsi_status = 0;
-                       } else if (resid != fw_resid_len) {
-                               scsi_status &= ~SS_RESIDUAL_UNDER;
-                               lscsi_status = 0;
+               resid = IS_FWI2_CAPABLE(ha) ? fw_resid_len : resid_len;
+               scsi_set_resid(cp, resid);
+               if (scsi_status & SS_RESIDUAL_UNDER) {
+                       if (IS_FWI2_CAPABLE(ha) && fw_resid_len != resid_len) {
+                               DEBUG2(printk(
+                                   "scsi(%ld:%d:%d:%d) Dropped frame(s) "
+                                   "detected (%x of %x bytes)...residual "
+                                   "length mismatch...retrying command.\n",
+                                   vha->host_no, cp->device->channel,
+                                   cp->device->id, cp->device->lun, resid,
+                                   scsi_bufflen(cp)));
+
+                               cp->result = DID_ERROR << 16 | lscsi_status;
+                               break;
                        }
-                       resid = fw_resid_len;
-               }
 
-               if (scsi_status & SS_RESIDUAL_UNDER) {
-                       scsi_set_resid(cp, resid);
-               } else {
-                       DEBUG2(printk(KERN_INFO
-                           "scsi(%ld:%d:%d) UNDERRUN status detected "
-                           "0x%x-0x%x. resid=0x%x fw_resid=0x%x cdb=0x%x "
-                           "os_underflow=0x%x\n", vha->host_no,
-                           cp->device->id, cp->device->lun, comp_status,
-                           scsi_status, resid_len, resid, cp->cmnd[0],
-                           cp->underflow));
+                       if (!lscsi_status &&
+                           ((unsigned)(scsi_bufflen(cp) - resid) <
+                           cp->underflow)) {
+                               qla_printk(KERN_INFO, ha,
+                                   "scsi(%ld:%d:%d:%d): Mid-layer underflow "
+                                   "detected (%x of %x bytes)...returning "
+                                   "error status.\n", vha->host_no,
+                                   cp->device->channel, cp->device->id,
+                                   cp->device->lun, resid, scsi_bufflen(cp));
 
+                               cp->result = DID_ERROR << 16;
+                               break;
+                       }
+               } else if (!lscsi_status) {
+                       DEBUG2(printk(
+                           "scsi(%ld:%d:%d:%d) Dropped frame(s) detected "
+                           "(%x of %x bytes)...firmware reported underrun..."
+                           "retrying command.\n", vha->host_no,
+                           cp->device->channel, cp->device->id,
+                           cp->device->lun, resid, scsi_bufflen(cp)));
+
+                       cp->result = DID_ERROR << 16;
+                       break;
                }
 
+               cp->result = DID_OK << 16 | lscsi_status;
+
                /*
                 * Check to see if SCSI Status is non zero. If so report SCSI
                 * Status.
                 */
                if (lscsi_status != 0) {
-                       cp->result = DID_OK << 16 | lscsi_status;
-
                        if (lscsi_status == SAM_STAT_TASK_SET_FULL) {
                                DEBUG2(printk(KERN_INFO
                                    "scsi(%ld): QUEUE FULL status detected "
@@ -1507,42 +1537,6 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct rsp_que *rsp, void *pkt)
                                break;
 
                        qla2x00_handle_sense(sp, sense_data, sense_len, rsp);
-               } else {
-                       /*
-                        * If RISC reports underrun and target does not report
-                        * it then we must have a lost frame, so tell upper
-                        * layer to retry it by reporting an error.
-                        */
-                       if (!(scsi_status & SS_RESIDUAL_UNDER)) {
-                               DEBUG2(printk("scsi(%ld:%d:%d:%d) Dropped "
-                                             "frame(s) detected (%x of %x bytes)..."
-                                             "retrying command.\n",
-                                       vha->host_no, cp->device->channel,
-                                       cp->device->id, cp->device->lun, resid,
-                                       scsi_bufflen(cp)));
-
-                               scsi_set_resid(cp, resid);
-                               cp->result = DID_ERROR << 16;
-                               break;
-                       }
-
-                       /* Handle mid-layer underflow */
-                       if ((unsigned)(scsi_bufflen(cp) - resid) <
-                           cp->underflow) {
-                               qla_printk(KERN_INFO, ha,
-                                          "scsi(%ld:%d:%d:%d): Mid-layer underflow "
-                                          "detected (%x of %x bytes)...returning "
-                                          "error status.\n", vha->host_no,
-                                          cp->device->channel, cp->device->id,
-                                          cp->device->lun, resid,
-                                          scsi_bufflen(cp));
-
-                               cp->result = DID_ERROR << 16;
-                               break;
-                       }
-
-                       /* Everybody online, looking good... */
-                       cp->result = DID_OK << 16;
                }
                break;