[SCSI] qla2xxx: Reduce request queue-size overhead with recent ISPs.

The original code to 'resize request-queues' based on iocb-counts
and employed during early ISP23xx testing was too
overly-pessimistic with regards to latencies in the firmware
pulling requests.  Recent ISPs can easily keep up processing a
stream of commands from an abbreviated (effectively, half the
original size) queue.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/qla2xxx/qla_def.h

@@ -176,8 +176,7 @@
 /* ISP request and response entry counts (37-65535) */
 #define REQUEST_ENTRY_CNT_2100		128	/* Number of request entries. */
 #define REQUEST_ENTRY_CNT_2200		2048	/* Number of request entries. */
-#define REQUEST_ENTRY_CNT_2XXX_EXT_MEM	4096	/* Number of request entries. */
-#define REQUEST_ENTRY_CNT_24XX		4096	/* Number of request entries. */
+#define REQUEST_ENTRY_CNT_24XX		2048	/* Number of request entries. */
 #define RESPONSE_ENTRY_CNT_2100		64	/* Number of response entries.*/
 #define RESPONSE_ENTRY_CNT_2300		512	/* Number of response entries.*/
 

drivers/scsi/qla2xxx/qla_init.c

@@ -20,7 +20,6 @@
 *  QLogic ISP2x00 Hardware Support Function Prototypes.
 */
 static int qla2x00_isp_firmware(scsi_qla_host_t *);
-static void qla2x00_resize_request_q(scsi_qla_host_t *);
 static int qla2x00_setup_chip(scsi_qla_host_t *);
 static int qla2x00_init_rings(scsi_qla_host_t *);
 static int qla2x00_fw_ready(scsi_qla_host_t *);
@@ -892,62 +891,6 @@ qla2x00_alloc_fw_dump(scsi_qla_host_t *vha)
 	    htonl(offsetof(struct qla2xxx_fw_dump, isp));
 }
 
-/**
- * qla2x00_resize_request_q() - Resize request queue given available ISP memory.
- * @ha: HA context
- *
- * Returns 0 on success.
- */
-static void
-qla2x00_resize_request_q(scsi_qla_host_t *vha)
-{
-	int rval;
-	uint16_t fw_iocb_cnt = 0;
-	uint16_t request_q_length = REQUEST_ENTRY_CNT_2XXX_EXT_MEM;
-	dma_addr_t request_dma;
-	request_t *request_ring;
-	struct qla_hw_data *ha = vha->hw;
-	struct req_que *req = ha->req_q_map[0];
-
-	/* Valid only on recent ISPs. */
-	if (IS_QLA2100(ha) || IS_QLA2200(ha))
-		return;
-
-	/* Retrieve IOCB counts available to the firmware. */
-	rval = qla2x00_get_resource_cnts(vha, NULL, NULL, NULL, &fw_iocb_cnt,
-					&ha->max_npiv_vports);
-	if (rval)
-		return;
-	/* No point in continuing if current settings are sufficient. */
-	if (fw_iocb_cnt < 1024)
-		return;
-	if (req->length >= request_q_length)
-		return;
-
-	/* Attempt to claim larger area for request queue. */
-	request_ring = dma_alloc_coherent(&ha->pdev->dev,
-	    (request_q_length + 1) * sizeof(request_t), &request_dma,
-	    GFP_KERNEL);
-	if (request_ring == NULL)
-		return;
-
-	/* Resize successful, report extensions. */
-	qla_printk(KERN_INFO, ha, "Extended memory detected (%d KB)...\n",
-	    (ha->fw_memory_size + 1) / 1024);
-	qla_printk(KERN_INFO, ha, "Resizing request queue depth "
-	    "(%d -> %d)...\n", req->length, request_q_length);
-
-	/* Clear old allocations. */
-	dma_free_coherent(&ha->pdev->dev,
-	    (req->length + 1) * sizeof(request_t), req->ring,
-	    req->dma);
-
-	/* Begin using larger queue. */
-	req->length = request_q_length;
-	req->ring = request_ring;
-	req->dma = request_dma;
-}
-
 /**
  * qla2x00_setup_chip() - Load and start RISC firmware.
  * @ha: HA context
@@ -1005,11 +948,11 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
 						ha->max_npiv_vports =
 						    MIN_MULTI_ID_FABRIC - 1;
 				}
-				if (!fw_major_version) {
-					qla2x00_resize_request_q(vha);
-					if (ql2xallocfwdump)
-						qla2x00_alloc_fw_dump(vha);
-				}
+				qla2x00_get_resource_cnts(vha, NULL, NULL,
+				    NULL, NULL, &ha->max_npiv_vports);
+
+				if (!fw_major_version && ql2xallocfwdump)
+					qla2x00_alloc_fw_dump(vha);
 			}
 		} else {
 			DEBUG2(printk(KERN_INFO