[SCSI] qla4xxx: Remove hiwat code so scsi eh does not get escalated when we can make...
Karen Higgins [Wed, 15 Jul 2009 20:03:02 +0000 (15:03 -0500)]
Removed unnecessary hiwat code to free up the number available IOCBs.
Eliminates unnecessary eh_ escalations due to inability to obtain IOCB
pkt for marker.

v2.
- Remove define not used anymore and fix req_q_coun accounting.

Signed-off-by: Karen Higgins <karen.higgins@qlogic.com>
[michaelc: ported patch from qlogic.com driver to upstream]
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/qla4xxx/ql4_def.h
drivers/scsi/qla4xxx/ql4_iocb.c
drivers/scsi/qla4xxx/ql4_mbx.c

index 963e855..81b5f29 100644 (file)
 #define MAX_SRBS               MAX_CMDS_TO_RISC
 #define MBOX_AEN_REG_COUNT     5
 #define MAX_INIT_RETRIES       5
-#define IOCB_HIWAT_CUSHION     16
 
 /*
  * Buffer sizes
@@ -307,7 +306,6 @@ struct scsi_qla_host {
        uint32_t tot_ddbs;
 
        uint16_t        iocb_cnt;
-       uint16_t        iocb_hiwat;
 
        /* SRB cache. */
 #define SRB_MIN_REQ    128
index 912a674..e0c3215 100644 (file)
 #include "ql4_dbg.h"
 #include "ql4_inline.h"
 
-
 #include <scsi/scsi_tcq.h>
 
+static int
+qla4xxx_space_in_req_ring(struct scsi_qla_host *ha, uint16_t req_cnt)
+{
+       uint16_t cnt;
+
+       /* Calculate number of free request entries. */
+       if ((req_cnt + 2) >= ha->req_q_count) {
+               cnt = (uint16_t) le32_to_cpu(ha->shadow_regs->req_q_out);
+               if (ha->request_in < cnt)
+                       ha->req_q_count = cnt - ha->request_in;
+               else
+                       ha->req_q_count = REQUEST_QUEUE_DEPTH -
+                                               (ha->request_in - cnt);
+       }
+
+       /* Check if room for request in request ring. */
+       if ((req_cnt + 2) < ha->req_q_count)
+               return 1;
+       else
+               return 0;
+}
+
+static void qla4xxx_advance_req_ring_ptr(struct scsi_qla_host *ha)
+{
+       /* Advance request queue pointer */
+       if (ha->request_in == (REQUEST_QUEUE_DEPTH - 1)) {
+               ha->request_in = 0;
+               ha->request_ptr = ha->request_ring;
+       } else {
+               ha->request_in++;
+               ha->request_ptr++;
+       }
+}
+
 /**
  * qla4xxx_get_req_pkt - returns a valid entry in request queue.
  * @ha: Pointer to host adapter structure.
 static int qla4xxx_get_req_pkt(struct scsi_qla_host *ha,
                               struct queue_entry **queue_entry)
 {
-       uint16_t request_in;
-       uint8_t status = QLA_SUCCESS;
-
-       *queue_entry = ha->request_ptr;
+       uint16_t req_cnt = 1;
 
-       /* get the latest request_in and request_out index */
-       request_in = ha->request_in;
-       ha->request_out = (uint16_t) le32_to_cpu(ha->shadow_regs->req_q_out);
-
-       /* Advance request queue pointer and check for queue full */
-       if (request_in == (REQUEST_QUEUE_DEPTH - 1)) {
-               request_in = 0;
-               ha->request_ptr = ha->request_ring;
-       } else {
-               request_in++;
-               ha->request_ptr++;
-       }
-
-       /* request queue is full, try again later */
-       if ((ha->iocb_cnt + 1) >= ha->iocb_hiwat) {
-               /* restore request pointer */
-               ha->request_ptr = *queue_entry;
-               status = QLA_ERROR;
-       } else {
-               ha->request_in = request_in;
+       if (qla4xxx_space_in_req_ring(ha, req_cnt)) {
+               *queue_entry = ha->request_ptr;
                memset(*queue_entry, 0, sizeof(**queue_entry));
+
+               qla4xxx_advance_req_ring_ptr(ha);
+               ha->req_q_count -= req_cnt;
+               return QLA_SUCCESS;
        }
 
-       return status;
+       return QLA_ERROR;
 }
 
 /**
@@ -100,21 +116,14 @@ exit_send_marker:
        return status;
 }
 
-static struct continuation_t1_entry* qla4xxx_alloc_cont_entry(
-       struct scsi_qla_host *ha)
+static struct continuation_t1_entry *
+qla4xxx_alloc_cont_entry(struct scsi_qla_host *ha)
 {
        struct continuation_t1_entry *cont_entry;
 
        cont_entry = (struct continuation_t1_entry *)ha->request_ptr;
 
-       /* Advance request queue pointer */
-       if (ha->request_in == (REQUEST_QUEUE_DEPTH - 1)) {
-               ha->request_in = 0;
-               ha->request_ptr = ha->request_ring;
-       } else {
-               ha->request_in++;
-               ha->request_ptr++;
-       }
+       qla4xxx_advance_req_ring_ptr(ha);
 
        /* Load packet defaults */
        cont_entry->hdr.entryType = ET_CONTINUE;
@@ -197,13 +206,10 @@ int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb)
        struct scsi_cmnd *cmd = srb->cmd;
        struct ddb_entry *ddb_entry;
        struct command_t3_entry *cmd_entry;
-
        int nseg;
        uint16_t tot_dsds;
        uint16_t req_cnt;
-
        unsigned long flags;
-       uint16_t cnt;
        uint32_t index;
        char tag[2];
 
@@ -217,6 +223,19 @@ int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb)
 
        index = (uint32_t)cmd->request->tag;
 
+       /*
+        * Check to see if adapter is online before placing request on
+        * request queue.  If a reset occurs and a request is in the queue,
+        * the firmware will still attempt to process the request, retrieving
+        * garbage for pointers.
+        */
+       if (!test_bit(AF_ONLINE, &ha->flags)) {
+               DEBUG2(printk("scsi%ld: %s: Adapter OFFLINE! "
+                             "Do not issue command.\n",
+                             ha->host_no, __func__));
+               goto queuing_error;
+       }
+
        /* Calculate the number of request entries needed. */
        nseg = scsi_dma_map(cmd);
        if (nseg < 0)
@@ -224,17 +243,7 @@ int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb)
        tot_dsds = nseg;
 
        req_cnt = qla4xxx_calc_request_entries(tot_dsds);
-
-       if (ha->req_q_count < (req_cnt + 2)) {
-               cnt = (uint16_t) le32_to_cpu(ha->shadow_regs->req_q_out);
-               if (ha->request_in < cnt)
-                       ha->req_q_count = cnt - ha->request_in;
-               else
-                       ha->req_q_count = REQUEST_QUEUE_DEPTH -
-                               (ha->request_in - cnt);
-       }
-
-       if (ha->req_q_count < (req_cnt + 2))
+       if (!qla4xxx_space_in_req_ring(ha, req_cnt))
                goto queuing_error;
 
        /* total iocbs active */
@@ -286,32 +295,10 @@ int qla4xxx_send_command_to_isp(struct scsi_qla_host *ha, struct srb * srb)
                        break;
                }
 
-
-       /* Advance request queue pointer */
-       ha->request_in++;
-       if (ha->request_in == REQUEST_QUEUE_DEPTH) {
-               ha->request_in = 0;
-               ha->request_ptr = ha->request_ring;
-       } else
-               ha->request_ptr++;
-
-
+       qla4xxx_advance_req_ring_ptr(ha);
        qla4xxx_build_scsi_iocbs(srb, cmd_entry, tot_dsds);
        wmb();
 
-       /*
-        * Check to see if adapter is online before placing request on
-        * request queue.  If a reset occurs and a request is in the queue,
-        * the firmware will still attempt to process the request, retrieving
-        * garbage for pointers.
-        */
-       if (!test_bit(AF_ONLINE, &ha->flags)) {
-               DEBUG2(printk("scsi%ld: %s: Adapter OFFLINE! "
-                             "Do not issue command.\n",
-                             ha->host_no, __func__));
-               goto queuing_error;
-       }
-
        srb->cmd->host_scribble = (unsigned char *)srb;
 
        /* update counters */
index 051b0f5..09d6d4b 100644 (file)
@@ -385,16 +385,6 @@ int qla4xxx_get_firmware_status(struct scsi_qla_host * ha)
                              mbox_sts[0]));
                return QLA_ERROR;
        }
-
-       /* High-water mark of IOCBs */
-       ha->iocb_hiwat = mbox_sts[2];
-       if (ha->iocb_hiwat > IOCB_HIWAT_CUSHION)
-               ha->iocb_hiwat -= IOCB_HIWAT_CUSHION;
-       else
-               dev_info(&ha->pdev->dev, "WARNING!!!  You have less than %d "
-                          "firmware IOCBs available (%d).\n",
-                          IOCB_HIWAT_CUSHION, ha->iocb_hiwat);
-
        return QLA_SUCCESS;
 }