[src/netbsd-1-4]: src/sys/dev/pci pull up rev 1.87 from trunk (requested by c...

[cgd <cgd%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/caaa7f9e89bb
branches:  netbsd-1-4
changeset: 469601:caaa7f9e89bb
user:      cgd <cgd%NetBSD.org@localhost>
date:      Mon Oct 18 05:43:11 1999 +0000

description:
pull up rev 1.87 from trunk (requested by cgd):
  Fix bugs in handling QUEUE FULL messages.  Also, when a QUEUE FULL
  message is seen, disable tagged queueing completely for the target
  which generated it.  This is (much) more conservative than necessary
  for normal operation, but allows the driver to function properly
  even with some broken drives at the cost of some performance on
  drives that have a very low tagged command limit.

diffstat:

 sys/dev/pci/ncr.c |  59 +++++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 49 insertions(+), 10 deletions(-)

diffs (114 lines):

diff -r ea62f9e06690 -r caaa7f9e89bb sys/dev/pci/ncr.c
--- a/sys/dev/pci/ncr.c Mon Oct 18 05:23:01 1999 +0000
+++ b/sys/dev/pci/ncr.c Mon Oct 18 05:43:11 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ncr.c,v 1.80.2.3 1999/09/18 01:12:25 cgd Exp $ */
+/*     $NetBSD: ncr.c,v 1.80.2.4 1999/10/18 05:43:11 cgd Exp $ */
 
 /**************************************************************************
 **
@@ -1356,8 +1356,8 @@
        ncrcmd  msg_bad         [  6];
        ncrcmd  complete        [ 13];
        ncrcmd  cleanup         [ 12];
-       ncrcmd  cleanup0        [ 11];
-       ncrcmd  signal          [ 10];
+       ncrcmd  cleanup0        [ 9];
+       ncrcmd  signal          [ 12];
        ncrcmd  save_dp         [  5];
        ncrcmd  restore_dp      [  5];
        ncrcmd  disconnect      [ 12];
@@ -1518,7 +1518,7 @@
 
 #if 0
 static char ident[] =
-       "\n$NetBSD: ncr.c,v 1.80.2.3 1999/09/18 01:12:25 cgd Exp $\n";
+       "\n$NetBSD: ncr.c,v 1.80.2.4 1999/10/18 05:43:11 cgd Exp $\n";
 #endif
 
 static const u_long    ncr_version = NCR_VERSION       * 11
@@ -2287,21 +2287,21 @@
                0,
        SCR_JUMP ^ IFTRUE (DATA (S_CHECK_COND)),
                PADDRH(getcc2),
-       /*
-       **      And make the DSA register invalid.
-       */
-/*>>>*/        SCR_LOAD_REG (dsa, 0xff), /* invalid */
-               0,
 }/*-------------------------< SIGNAL >----------------------*/,{
        /*
        **      if status = queue full,
        **      reinsert in startqueue and stall queue.
        */
-       SCR_FROM_REG (SS_REG),
+/*>>>*/        SCR_FROM_REG (SS_REG),
                0,
        SCR_INT ^ IFTRUE (DATA (S_QUEUE_FULL)),
                SIR_STALL_QUEUE,
        /*
+       **      And make the DSA register invalid.
+       */
+       SCR_LOAD_REG (dsa, 0xff), /* invalid */
+               0,
+       /*
        **      if job completed ...
        */
        SCR_FROM_REG (HS_REG),
@@ -5836,8 +5836,19 @@
        tmp = lp->actlink;
        if (tmp < reqtags) tmp = reqtags;
        lp->reqccbs = tmp;
+
+#if 0
+       /*
+        * XXX unless we do this, we'll end up wasting ccbs (since
+        * XXX they are never freed back to the system), but wasting
+        * XXX CCBs is better than keeping reqlink high, because that
+        * XXX allows high numbers of tags to continue to be used...
+        * XXX which in turn prevents 'queue full' problems from ever
+        * XXX being solved.
+        */
        if (lp->reqlink < lp->reqccbs)
                lp->reqlink = lp->reqccbs;
+#endif
 }
 
 /*----------------------------------------------------
@@ -7236,8 +7247,36 @@
 
                /*
                **      Try to disable tagged transfers.
+               **
+               **      XXX The right thing to do here is to back off
+               **      XXX gracefully, i.e. issue one fewer command
+               **      XXX at a time, since this command should be
+               **      XXX triggered by the first command beyond what
+               **      XXX the device can handle.
+               **      XXX
+               **      XXX However, that doesn't work right now, because
+               **      XXX of a combination of two bugs: some (Quantum)
+               **      XXX drives seem to interpret the tags (tags are
+               **      XXX supposed to be opaque) and reject tags over
+               **      XXX a certain number, and this driver doesn't free
+               **      XXX 'extra' CCBs which will never be used for
+               **      XXX transfters (based on the fact that there are
+               **      XXX more CCBs than tags allowed).
+               **      XXX
+               **      XXX Therefore, though it costs performance on
+               **      XXX some drives that could do better, for hardware
+               **      XXX compatibility we just disable tagged queueing
+               **      XXX when we see a QUEUE FULL message.
+               **      XXX
+               **      XXX This driver should be shot from a cannon.
                */
+#if 0 /* XXX this, or something like it, is better, but doesn't work */
+               assert(cp->tag);
+               if (cp->tag) /* XXX should be a better way than cp->tag - 1 */
+                       ncr_setmaxtags (&np->target[target], cp->tag - 1);
+#else
                ncr_setmaxtags (&np->target[target], 0);
+#endif
 
                /*
                ** @QUEUE@