Don't issue a linked command to check for a device's support of them.

Instead, check the inquiry_flag.  Also allow enabling and disabling
linked command issuance on target-by-target basis.

diff --git a/sys/arch/mac68k/dev/ncr5380.c b/sys/arch/mac68k/dev/ncr5380.c
index 2c8fe5e..99a620f 100644 (file)
--- a/sys/arch/mac68k/dev/ncr5380.c
+++ b/sys/arch/mac68k/dev/ncr5380.c
@@ -74,16 +74,18 @@ u_char      dbg_target_mask = 0x7f;
  */
 u_char ncr5380_no_parchk = 0xff;
 
-#ifdef AUTO_SENSE
-
 /*
- * Bit masks of targets that accept linked commands, and those
- * that we've already checked out
+ * Flags to allow binpatching of which devices to allow or disallow
+ * issuance of linked commands.  disallowance is favored over allowance,
+ * so if the same bit is set in either, the driver will not issue linked
+ * commands to the corresponding target.
+ * SCSI-2 devices can report whether or not they will accept linked
+ * commands.  If that reports that a device supports linked commands,
+ * then it is treated as if the corresponding bit in ncr5380_allow_linked
+ * is set.
  */
-u_char ncr_will_link = 0x00;
-u_char ncr_test_link = 0x00;
-
-#endif /* AUTO_SENSE */
+u_char ncr5380_allow_linked = 0x80;
+u_char ncr5380_disallow_linked = 0x80;
 
 /*
  * This is the default sense-command we send.
@@ -405,46 +407,14 @@ ncr5380_scsi_cmd(struct scsi_xfer *xs)
                } while (tmp->next && (tmp = tmp->next));
                tmp->next = reqp;
 #ifdef AUTO_SENSE
-               if (link && (ncr_will_link & (1<<reqp->targ_id))) {
+               if (link && (   (xs->sc_link->inquiry_flags & SID_Linked)
+                            || ((1<<reqp->targ_id) & ncr5380_allow_linked))
+                        && !((1<<reqp->targ_id) & ncr5380_disallow_linked)) {
                        link->link = reqp;
                        link->xcmd.bytes[link->xs->cmdlen-2] |= 1;
                }
 #endif
        }
-#ifdef AUTO_SENSE
-       /*
-        * If we haven't already, check the target for link support.
-        * Do this by prefixing the current command with a dummy
-        * Request_Sense command, link the dummy to the current
-        * command, and insert the dummy command at the head of the
-        * issue queue.  Set the DRIVER_LINKCHK flag so that we'll
-        * ignore the results of the dummy command, since we only
-        * care about whether it was accepted or not.
-        */
-       if (!link && !(ncr_test_link & (1<<reqp->targ_id)) &&
-           (tmp = free_head) && !(reqp->dr_flag & DRIVER_NOINT)) {
-               free_head = tmp->next;
-               tmp->dr_flag = (reqp->dr_flag & ~DRIVER_DMAOK) | DRIVER_LINKCHK;
-               tmp->phase = NR_PHASE;
-               tmp->msgout = MSG_NOOP;
-               tmp->status = SCSGOOD;
-               tmp->xs = reqp->xs;
-               tmp->targ_id = reqp->targ_id;
-               tmp->targ_lun = reqp->targ_lun;
-               bcopy(sense_cmd, &tmp->xcmd, sizeof(sense_cmd));
-               tmp->xdata_ptr = (u_char *)&tmp->xs->sense;
-               tmp->xdata_len = sizeof(tmp->xs->sense);
-               ncr_test_link |= 1<<tmp->targ_id;
-               tmp->link = reqp;
-               tmp->xcmd.bytes[sizeof(sense_cmd)-2] |= 1;
-               tmp->next = issue_q;
-               issue_q = tmp;
-#ifdef DBG_REQ
-               if (dbg_target_mask & (1 << tmp->targ_id))
-                       show_request(tmp, "LINKCHK");
-#endif
-       }
-#endif
        splx(sps);
 
 #ifdef DBG_REQ
@@ -893,8 +863,6 @@ SC_REQ      *reqp;
                        reqp->xs->error      = code ? code : XS_SELTIMEOUT;
                        DBG_SELPRINT ("Target %d not responding to sel\n",
                                                                reqp->targ_id);
-                       if (reqp->dr_flag & DRIVER_LINKCHK)
-                               ncr_test_link &= ~(1<<reqp->targ_id);
                        finish_req(reqp);
                        PID("scsi_select8");
                        return (0);
@@ -1583,18 +1551,6 @@ int      linked;
 {
        int     sps;
 
-       /*
-        * If this is the driver's Link Check for this target, ignore
-        * the results of the command.  All we care about is whether we
-        * got here from a LINK_CMD_COMPLETE or CMD_COMPLETE message.
-        */
-       PID("linkcheck");
-       if (reqp->dr_flag & DRIVER_LINKCHK) {
-               if (linked)
-                       ncr_will_link |= 1<<reqp->targ_id;
-               else ncr_tprint(reqp, "Does not support linked commands\n");
-               return (0);
-       }
        /*
         * If we not executing an auto-sense and the status code
         * is request-sense, we automatically issue a request