[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, 8 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index b455c31405e4..522bb2d3f084 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -823,6 +823,11 @@ typedef struct {
 #define PD_STATE_WAIT_PORT_LOGOUT_ACK           11
 
 
+#define QLA_ZIO_MODE_5          (BIT_2 | BIT_0)
+#define QLA_ZIO_MODE_6          (BIT_2 | BIT_1)
+#define QLA_ZIO_DISABLED        0
+#define QLA_ZIO_DEFAULT_TIMER   2
+
 /*
  * ISP Initialization Control Block.
  * Little endian except where noted.
@@ -2470,6 +2475,9 @@ typedef struct scsi_qla_host {
         /* Needed for BEACON */
         uint16_t        beacon_blink_led;
         uint16_t        beacon_green_on;
+
+        uint16_t        zio_mode;
+        uint16_t        zio_timer;
 } scsi_qla_host_t;