[src/trunk]: src/sys/dev/pci Bump the Tx DMA segment count to 40. Apparently...

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

details:   https://anonhg.NetBSD.org/src/rev/bcc2a574f8b3
branches:  trunk
changeset: 555903:bcc2a574f8b3
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Thu Dec 04 06:57:37 2003 +0000

description:
Bump the Tx DMA segment count to 40.  Apparently, it's common to have
DMA segment counts in this ballpark when using jumbo frames (so says
the "ti" driver).

diffstat:

 sys/dev/pci/if_wm.c |  36 ++++++++++++++++++++++++++++++------
 1 files changed, 30 insertions(+), 6 deletions(-)

diffs (72 lines):

diff -r da7dd69f0b8b -r bcc2a574f8b3 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Thu Dec 04 06:33:14 2003 +0000
+++ b/sys/dev/pci/if_wm.c       Thu Dec 04 06:57:37 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.63 2003/11/22 08:32:12 thorpej Exp $       */
+/*     $NetBSD: if_wm.c,v 1.64 2003/12/04 06:57:37 thorpej Exp $       */
 
 /*
  * Copyright (c) 2001, 2002, 2003 Wasabi Systems, Inc.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.63 2003/11/22 08:32:12 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.64 2003/12/04 06:57:37 thorpej Exp $");
 
 #include "bpfilter.h"
 #include "rnd.h"
@@ -115,10 +115,11 @@
  * Transmit descriptor list size.  Due to errata, we can only have
  * 256 hardware descriptors in the ring.  We tell the upper layers
  * that they can queue a lot of packets, and we go ahead and manage
- * up to 64 of them at a time.  We allow up to 16 DMA segments per
- * packet.
+ * up to 64 of them at a time.  We allow up to 40 DMA segments per
+ * packet (there have been reports of jumbo frame packets with as
+ * many as 30 DMA segments!).
  */
-#define        WM_NTXSEGS              16
+#define        WM_NTXSEGS              40
 #define        WM_IFQUEUELEN           256
 #define        WM_TXQUEUELEN           64
 #define        WM_TXQUEUELEN_MASK      (WM_TXQUEUELEN - 1)
@@ -591,7 +592,7 @@
 };
 
 #ifdef WM_EVENT_COUNTERS
-#if WM_NTXSEGS != 16
+#if WM_NTXSEGS != 40
 #error Update wm_txseg_evcnt_names
 #endif
 static const char *wm_txseg_evcnt_names[WM_NTXSEGS] = {
@@ -611,6 +612,29 @@
        "txseg14",
        "txseg15",
        "txseg16",
+       "txseg17",
+       "txseg18",
+       "txseg19",
+       "txseg21",
+       "txseg22",
+       "txseg23",
+       "txseg24",
+       "txseg25",
+       "txseg26",
+       "txseg27",
+       "txseg28",
+       "txseg29",
+       "txseg30",
+       "txseg31",
+       "txseg32",
+       "txseg33",
+       "txseg34",
+       "txseg35",
+       "txseg36",
+       "txseg37",
+       "txseg38",
+       "txseg39",
+       "txseg40",
 };
 #endif /* WM_EVENT_COUNTERS */