[src/trunk]: src/sys/arch/sparc64/dev psycho_sabre_dmamap_sync: do nothing if...

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

details:   https://anonhg.NetBSD.org/src/rev/db43e17e26bd
branches:  trunk
changeset: 756273:db43e17e26bd
user:      nakayama <nakayama%NetBSD.org@localhost>
date:      Sat Jul 10 10:07:40 2010 +0000

description:
psycho_sabre_dmamap_sync: do nothing if len == 0 like iommu_dvmamap_sync.

diffstat:

 sys/arch/sparc64/dev/psycho.c |  19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diffs (41 lines):

diff -r 6fa2ce50a97c -r db43e17e26bd sys/arch/sparc64/dev/psycho.c
--- a/sys/arch/sparc64/dev/psycho.c     Sat Jul 10 08:48:47 2010 +0000
+++ b/sys/arch/sparc64/dev/psycho.c     Sat Jul 10 10:07:40 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: psycho.c,v 1.100 2010/01/06 05:55:01 mrg Exp $ */
+/*     $NetBSD: psycho.c,v 1.101 2010/07/10 10:07:40 nakayama Exp $    */
 
 /*
  * Copyright (c) 1999, 2000 Matthew R. Green
@@ -55,7 +55,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: psycho.c,v 1.100 2010/01/06 05:55:01 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: psycho.c,v 1.101 2010/07/10 10:07:40 nakayama Exp $");
 
 #include "opt_ddb.h"
 
@@ -1475,11 +1475,18 @@
 psycho_sabre_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
        bus_size_t len, int ops)
 {
-       struct psycho_pbm *pp = (struct psycho_pbm *)t->_cookie;
-       struct psycho_softc *sc = pp->pp_sc;
+       struct psycho_pbm *pp;
+       struct psycho_softc *sc;
+
+       /* If len is 0, then there is nothing to do. */
+       if (len == 0)
+               return;
 
-       if (ops & BUS_DMASYNC_POSTREAD)
+       if (ops & BUS_DMASYNC_POSTREAD) {
+               pp = (struct psycho_pbm *)t->_cookie;
+               sc = pp->pp_sc;
                bus_space_read_8(sc->sc_bustag, sc->sc_bh,
-                       offsetof(struct psychoreg, pci_dma_write_sync));
+                   offsetof(struct psychoreg, pci_dma_write_sync));
+       }
        bus_dmamap_sync(t->_parent, map, offset, len, ops);
 }