[SCSI] qla2xxx: Use FW calculated residual count for underrun handling.

With ISP24XX and ISP54XX parts.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 13 insertions, 5 deletions

diff --git a/drivers/scsi/qla2xxx/qla_fw.h b/drivers/scsi/qla2xxx/qla_fw.h
index 1ee58ad2f4dd..d2f5870628da 100644
--- a/drivers/scsi/qla2xxx/qla_fw.h
+++ b/drivers/scsi/qla2xxx/qla_fw.h
@@ -463,7 +463,7 @@ struct sts_entry_24xx {
         uint16_t comp_status;           /* Completion status. */
         uint16_t ox_id;                 /* OX_ID used by the firmware. */
 
-        uint32_t residual_len;          /* Residual transfer length. */
+        uint32_t residual_len;          /* FW calc residual transfer length. */
 
         uint16_t reserved_1;
         uint16_t state_flags;           /* State flags. */
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 2003dbb70579..40325ec70056 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -805,7 +805,7 @@ qla2x00_status_entry(scsi_qla_host_t *ha, void *pkt)
         uint16_t        scsi_status;
         uint8_t         lscsi_status;
         int32_t         resid;
-        uint32_t        sense_len, rsp_info_len, resid_len;
+        uint32_t        sense_len, rsp_info_len, resid_len, fw_resid_len;
         uint8_t         *rsp_info, *sense_data;
 
         sts = (sts_entry_t *) pkt;
@@ -859,11 +859,12 @@ qla2x00_status_entry(scsi_qla_host_t *ha, void *pkt)
 
         fcport = sp->fcport;
 
-        sense_len = rsp_info_len = resid_len = 0;
+        sense_len = rsp_info_len = resid_len = fw_resid_len = 0;
         if (IS_QLA24XX(ha) || IS_QLA54XX(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);
                 rsp_info = sts24->data;
                 sense_data = sts24->data;
                 host_to_fcp_swap(sts24->data, sizeof(sts24->data));
@@ -963,14 +964,21 @@ qla2x00_status_entry(scsi_qla_host_t *ha, void *pkt)
 
         case CS_DATA_UNDERRUN:
                 resid = resid_len;
+                /* Use F/W calculated residual length. */
+                if (IS_QLA24XX(ha) || IS_QLA54XX(ha))
+                        resid = fw_resid_len;
+
                 if (scsi_status & SS_RESIDUAL_UNDER) {
                         cp->resid = resid;
                         CMD_RESID_LEN(cp) = resid;
                 } else {
                         DEBUG2(printk(KERN_INFO
                             "scsi(%ld:%d:%d) UNDERRUN status detected "
-                            "0x%x-0x%x.\n", ha->host_no, cp->device->id,
-                            cp->device->lun, comp_status, scsi_status));
+                            "0x%x-0x%x. resid=0x%x fw_resid=0x%x cdb=0x%x "
+                            "os_underflow=0x%x\n", ha->host_no,
+                            cp->device->id, cp->device->lun, comp_status,
+                            scsi_status, resid_len, resid, cp->cmnd[0],
+                            cp->underflow));
 
                 }