[src/trunk]: src/sys/dev/pci Do I219 TX DMA workaround only when TDLEN(0) != 0

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

details:   https://anonhg.NetBSD.org/src/rev/d012b308d268
branches:  trunk
changeset: 345163:d012b308d268
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Wed May 11 02:23:50 2016 +0000

description:
Do I219 TX DMA workaround only when TDLEN(0) != 0

diffstat:

 sys/dev/pci/if_wm.c |  10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diffs (31 lines):

diff -r 4a0d2169cc01 -r d012b308d268 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Wed May 11 02:18:27 2016 +0000
+++ b/sys/dev/pci/if_wm.c       Wed May 11 02:23:50 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.394 2016/05/06 10:56:04 msaitoh Exp $      */
+/*     $NetBSD: if_wm.c,v 1.395 2016/05/11 02:23:50 msaitoh Exp $      */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -83,7 +83,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.394 2016/05/06 10:56:04 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.395 2016/05/11 02:23:50 msaitoh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -5172,7 +5172,11 @@
 
                        preg = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
                            WM_PCI_DESCRING_STATUS);
-                       if (preg & DESCRING_STATUS_FLUSH_REQ) {
+                       reg = CSR_READ(sc, WMREG_TDLEN(0));
+                       printf("XXX RST: FLUSH = %lu, len = %u\n",
+                           preg & DESCRING_STATUS_FLUSH_REQ, reg);
+                       if (((preg & DESCRING_STATUS_FLUSH_REQ) != 0)
+                           && (reg != 0)) {
                                /* TX */
                                printf("XXX need TX flush (reg = %08x)\n",
                                    preg);