[src/trunk]: src/sys/dev/ic change DIOCCACHESYNC to not issue the FLUSH comma...

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

details:   https://anonhg.NetBSD.org/src/rev/c0a2f67cc442
branches:  trunk
changeset: 351833:c0a2f67cc442
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Feb 28 20:55:09 2017 +0000

description:
change DIOCCACHESYNC to not issue the FLUSH command at all when the controller
has no volatile write cache

diffstat:

 sys/dev/ic/ld_nvme.c |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (30 lines):

diff -r 3acda8c7681e -r c0a2f67cc442 sys/dev/ic/ld_nvme.c
--- a/sys/dev/ic/ld_nvme.c      Tue Feb 28 20:53:50 2017 +0000
+++ b/sys/dev/ic/ld_nvme.c      Tue Feb 28 20:55:09 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ld_nvme.c,v 1.13 2017/02/28 20:53:50 jdolecek Exp $    */
+/*     $NetBSD: ld_nvme.c,v 1.14 2017/02/28 20:55:09 jdolecek Exp $    */
 
 /*-
  * Copyright (C) 2016 NONAKA Kimihiro <nonaka%netbsd.org@localhost>
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ld_nvme.c,v 1.13 2017/02/28 20:53:50 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ld_nvme.c,v 1.14 2017/02/28 20:55:09 jdolecek Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -199,6 +199,11 @@
 {
        struct ld_nvme_softc *sc = device_private(ld->sc_dv);
 
+       if (!nvme_has_volatile_write_cache(sc->sc_nvme)) {
+               /* cache not present, no value in trying to flush it */
+               return 0;
+       }
+
        return nvme_ns_sync(sc->sc_nvme, sc->sc_nsid, sc,
            poll ? NVME_NS_CTX_F_POLL : 0,
            ld_nvme_syncdone);