From: Marcus Barrow <mbarrow@redhat.com>
Date: Thu, 25 Jun 2009 15:06:49 -0400
Subject: [scsi] qla4xxx: extended sense data errors, cleanups
Message-id: 20090625190649.11544.13561.sendpatchset@file.bos.redhat.com
O-Subject: [rhel 5.4 patch] [V2] qla4xxx - Testing updates
Bugzilla: 506981
RH-Acked-by: Mike Christie <mchristi@redhat.com>
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>

BZ 506981

Version 2 of this patch contains a missing line from the original
version. The count of items in request queue was not maintained.

This patch provides fixes for four issues found during testing at
QLogic.

qla4xxx - Testing fixes, update 2.

 - Removed unused hiwat code to free up the number available IOCBs.
Eliminates unnecessary eh_ escalations due to inability to obtain
IOCB pkt for marker.

 - Fixed NULL pointer dereference in eh_device_reset.
eh_device_reset may be called from scsi error handler or sg_reset, etc.
When called from sg_reset, there will not be an associated srb.
Also removed DEAD code (marker_needed variable in ha struct)

 - Code Cleanup - Removed residual from overrun debug print as
residual is only valid for underrun case.

 - RH BZ# 489389 - Extended Sense Data Errors-UPDATE
Updated algorithm to use srb data variables instead of scsi command
scratchpad data area, as scratchpad area is already used.

diff --git a/drivers/scsi/qla4xxx/ql4_def.h b/drivers/scsi/qla4xxx/ql4_def.h
index f5d2919..9a3f370 100644
--- a/drivers/scsi/qla4xxx/ql4_def.h
+++ b/drivers/scsi/qla4xxx/ql4_def.h
@@ -100,7 +100,6 @@
 #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
@@ -186,6 +185,11 @@ struct srb {
 	uint16_t cc_stat;
 	u_long r_start;		/* Time we recieve a cmd from OS */
 	u_long u_start;		/* Time when we handed the cmd to F/W */
+
+	/* Used for extended sense / status continuation */
+	uint8_t *req_sense_ptr;
+	uint16_t req_sense_len;
+	uint16_t reserved2;
 };
 
 	/*
@@ -314,7 +318,7 @@ struct scsi_qla_host {
 #define DPC_GET_DHCP_IP_ADDR	     15 /* 0x00008000 */
 
 	uint16_t	iocb_cnt;
-	uint16_t	iocb_hiwat;
+	uint16_t	rsvd;
 
 	/* SRB cache. */
 #define SRB_MIN_REQ	128
@@ -329,8 +333,7 @@ struct scsi_qla_host {
 #define MIN_IOBASE_LEN		0x100
 
 	uint16_t req_q_count;
-	uint8_t marker_needed;
-	uint8_t rsvd1;
+	uint8_t rsvd1[2];
 
 	unsigned long host_no;
 
@@ -436,6 +439,7 @@ struct scsi_qla_host {
 	uint16_t aen_out;
 	struct aen aen_q[MAX_AEN_ENTRIES];
 
+	/* Placeholder for original srb of status continuation */
         struct srb *status_srb;
 
         /* reserved fields */
diff --git a/drivers/scsi/qla4xxx/ql4_iocb.c b/drivers/scsi/qla4xxx/ql4_iocb.c
index f50e9f8..3856fa3 100644
--- a/drivers/scsi/qla4xxx/ql4_iocb.c
+++ b/drivers/scsi/qla4xxx/ql4_iocb.c
@@ -27,32 +27,37 @@
 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;
-
-	/* 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);
+	uint8_t	  status = QLA_ERROR;
+	uint16_t  cnt;
+	uint16_t  req_cnt = 1;
 
-	/* 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++;
+	/* 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);
+		}
 	}
 
-	/* 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;
+	/* Check if room for request in request ring. */
+	if ((req_cnt + 2) < ha->req_q_count) {
+		*queue_entry = ha->request_ptr;
 		memset(*queue_entry, 0, sizeof(**queue_entry));
+
+		/* 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++;
+		}
+		ha->req_q_count -= req_cnt;
+		status = QLA_SUCCESS;
 	}
 
 	return status;
diff --git a/drivers/scsi/qla4xxx/ql4_isr.c b/drivers/scsi/qla4xxx/ql4_isr.c
index bd776ce..22501d0 100644
--- a/drivers/scsi/qla4xxx/ql4_isr.c
+++ b/drivers/scsi/qla4xxx/ql4_isr.c
@@ -32,16 +32,15 @@ static void qla4xxx_copy_sense(struct scsi_qla_host *ha,
 	/* Save total available sense length,
 	 * not to exceed cmd's sense buffer size */
 	sense_len = min(sense_len, (uint16_t) SCSI_SENSE_BUFFERSIZE);
-	cmd->SCp.ptr = cmd->sense_buffer;
-	cmd->SCp.this_residual = sense_len;
+	srb->req_sense_ptr = cmd->sense_buffer;
+	srb->req_sense_len = sense_len;
 
 	/* Copy sense from sts_entry pkt */
 	sense_len = min(sense_len, (uint16_t) IOCB_MAX_SENSEDATA_LEN);
 	memcpy(cmd->sense_buffer, sts_entry->senseData, sense_len);
 
 	DEBUG2(printk("scsi%ld:%d:%d:%d: %s: sense key = %x, "
-		"Addl.SenseLen - %02x, "
-		"ASC/ASCQ = %02x/%02x\n", ha->host_no,
+		"ASL = %02x, ASC/ASCQ = %02x/%02x\n", ha->host_no,
 		cmd->device->channel, cmd->device->id,
 		cmd->device->lun, __func__,
 		sts_entry->senseData[2] & 0x0f,
@@ -49,13 +48,13 @@ static void qla4xxx_copy_sense(struct scsi_qla_host *ha,
 		sts_entry->senseData[12],
 		sts_entry->senseData[13]));
 
-	DEBUG5(qla4xxx_dump_buffer(cmd->SCp.ptr, sense_len));
+	DEBUG5(qla4xxx_dump_buffer(cmd->sense_buffer, sense_len));
 	srb->flags |= SRB_GOT_SENSE;
 
 	/* Update srb, in case a sts_cont pkt follows */
-	cmd->SCp.ptr += sense_len;
-	cmd->SCp.this_residual -= sense_len;
-	if (cmd->SCp.this_residual != 0)
+	srb->req_sense_ptr += sense_len;
+	srb->req_sense_len -= sense_len;
+	if (srb->req_sense_len != 0)
 		ha->status_srb = srb;
 	else
 		ha->status_srb = NULL;
@@ -75,13 +74,10 @@ qla4xxx_status_cont_entry(struct scsi_qla_host *ha,
 {
 	struct srb *srb = ha->status_srb;
 	struct scsi_cmnd *cmd;
-	uint8_t sense_len;
+	uint16_t sense_len;
 
-	if (srb == NULL) {
-		DEBUG2(printk("scsi%ld: %s: Throw away extra STATUS CONTINUATION\n",
-			ha->host_no, __func__));
+	if (srb == NULL)
 		return;
-	}
 
 	cmd = srb->cmd;
 	if (cmd == NULL) {
@@ -92,15 +88,15 @@ qla4xxx_status_cont_entry(struct scsi_qla_host *ha,
 	}
 
 	/* Copy sense data. */
-	sense_len = min(cmd->SCp.this_residual, IOCB_MAX_EXT_SENSEDATA_LEN);
-	memcpy(cmd->SCp.ptr, sts_cont->extSenseData, sense_len);
-	DEBUG5(qla4xxx_dump_buffer(cmd->SCp.ptr, sense_len));
+	sense_len = min(srb->req_sense_len, (uint16_t) IOCB_MAX_EXT_SENSEDATA_LEN);
+	memcpy(srb->req_sense_ptr, sts_cont->extSenseData, sense_len);
+	DEBUG5(qla4xxx_dump_buffer(srb->req_sense_ptr, sense_len));
 
-	cmd->SCp.ptr += sense_len;
-	cmd->SCp.this_residual -= sense_len;
+	srb->req_sense_ptr += sense_len;
+	srb->req_sense_len -= sense_len;
 
 	/* Place command on done queue. */
-	if (cmd->SCp.this_residual == 0) {
+	if (srb->req_sense_len == 0) {
 		qla4xxx_srb_compl(ha, srb);
 		ha->status_srb = NULL;
 	}
@@ -212,10 +208,10 @@ static void qla4xxx_status_entry(struct scsi_qla_host *ha,
 	case SCS_DATA_OVERRUN:
 		if ((sts_entry->iscsiFlags & ISCSI_FLAG_RESIDUAL_OVER) ||
 			(sts_entry->completionStatus == SCS_DATA_OVERRUN)) {
-			DEBUG2(printk("scsi%ld:%d:%d:%d: %s: " "Data overrun, "
-				      "residual = 0x%x\n", ha->host_no,
+			DEBUG2(printk("scsi%ld:%d:%d:%d: %s: "
+				      "Data overrun\n", ha->host_no,
 				      cmd->device->channel, cmd->device->id,
-				      cmd->device->lun, __func__, residual));
+				      cmd->device->lun, __func__));
 
 			cmd->result = DID_ERROR << 16;
 			break;
diff --git a/drivers/scsi/qla4xxx/ql4_mbx.c b/drivers/scsi/qla4xxx/ql4_mbx.c
index 64d9783..71fef48 100644
--- a/drivers/scsi/qla4xxx/ql4_mbx.c
+++ b/drivers/scsi/qla4xxx/ql4_mbx.c
@@ -469,15 +469,6 @@ int qla4xxx_get_firmware_status(struct scsi_qla_host * ha)
 		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 "
-			   "firmare IOCBs available (%d).\n",
-			   IOCB_HIWAT_CUSHION, ha->iocb_hiwat);
-
 	return QLA_SUCCESS;
 }
 
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 45d2d45..843b010 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -1546,11 +1546,9 @@ static int qla4xxx_eh_device_reset(struct scsi_cmnd *cmd)
 {
 	struct scsi_qla_host *ha = to_qla_host(cmd->device->host);
 	struct ddb_entry *ddb_entry = cmd->device->hostdata;
-	struct srb *sp;
 	int ret = FAILED, stat;
 
-	sp = (struct srb *) cmd->SCp.ptr;
-	if (!sp || !ddb_entry)
+	if (!ddb_entry)
 		return ret;
 
 	dev_info(&ha->pdev->dev,