scsi: esp_scsi: Grant disconnect privilege for untagged commands

A SCSI device is not granted disconnect privilege by an esp_scsi host
unless that device has its simple_tags flag set. However, a device may
support disconnect/reselect and not support command queueing. Allow such
devices to disconnect and thereby improve bus utilization.

Drop the redundant 'lp' check. The mid-layer invokes .slave_alloc and
.slave_destroy in such a way that we may rely on scmd->device->hostdata
for as long as scmd belongs to the low-level driver.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index cba58cf..6924614 100644 (file)
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -736,7 +736,6 @@ static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp)
 static void esp_maybe_execute_command(struct esp *esp)
 {
        struct esp_target_data *tp;
-       struct esp_lun_data *lp;
        struct scsi_device *dev;
        struct scsi_cmnd *cmd;
        struct esp_cmd_entry *ent;
@@ -762,7 +761,6 @@ static void esp_maybe_execute_command(struct esp *esp)
        tgt = dev->id;
        lun = dev->lun;
        tp = &esp->target[tgt];
-       lp = dev->hostdata;
 
        list_move(&ent->list, &esp->active_cmds);
 
@@ -818,14 +816,7 @@ static void esp_maybe_execute_command(struct esp *esp)
        }
 
 build_identify:
-       /* If we don't have a lun-data struct yet, we're probing
-        * so do not disconnect.  Also, do not disconnect unless
-        * we have a tag on this command.
-        */
-       if (lp && (tp->flags & ESP_TGT_DISCONNECT) && ent->tag[0])
-               *p++ = IDENTIFY(1, lun);
-       else
-               *p++ = IDENTIFY(0, lun);
+       *p++ = IDENTIFY(tp->flags & ESP_TGT_DISCONNECT, lun);
 
        if (ent->tag[0] && esp->rev == ESP100) {
                /* ESP100 lacks select w/atn3 command, use select