[SCSI] qla2xxx: Add support to dynamically enable/disable ZIO.

ISP23xx and ISP24xx chips have support for an adaptive
method of posting SCSI command completions for multiple SCSI
commands during a single system interrupt.

SCSI commands are placed on the system response queue
without interrupting the host until 1) a delay timer
expires; or 2) a SCSI command completes with an error.

As long as the host software (qla2xxx) services the response
queue for completions (this polling is done during
queuecommand()) within the 'delay timer' period, the
firmware will not generate system interrupt.

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

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index c255bb0268a9..cf6c6ce0b42b 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -21,13 +21,11 @@
 static void qla2x00_mbx_completion(scsi_qla_host_t *, uint16_t);
 static void qla2x00_async_event(scsi_qla_host_t *, uint16_t *);
 static void qla2x00_process_completed_request(struct scsi_qla_host *, uint32_t);
-void qla2x00_process_response_queue(struct scsi_qla_host *);
 static void qla2x00_status_entry(scsi_qla_host_t *, void *);
 static void qla2x00_status_cont_entry(scsi_qla_host_t *, sts_cont_entry_t *);
 static void qla2x00_error_entry(scsi_qla_host_t *, sts_entry_t *);
 static void qla2x00_ms_entry(scsi_qla_host_t *, ms_iocb_entry_t *);
 
-void qla24xx_process_response_queue(scsi_qla_host_t *);
 static void qla24xx_ms_entry(scsi_qla_host_t *, struct ct_entry_24xx *);
 
 /**
@@ -651,7 +649,10 @@ qla2x00_async_event(scsi_qla_host_t *ha, uint16_t *mb)
                     "scsi(%ld): [R|Z]IO update completion.\n",
                     ha->host_no));
 
-                qla2x00_process_response_queue(ha);
+                if (IS_QLA24XX(ha) || IS_QLA25XX(ha))
+                        qla24xx_process_response_queue(ha);
+                else
+                        qla2x00_process_response_queue(ha);
                 break;
 
         case MBA_DISCARD_RND_FRAME: