[src/trunk]: src/sys/dev/scsipi Create a dedicated thread for the initial scs...

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

details:   https://anonhg.NetBSD.org/src/rev/599ae91043dc
branches:  trunk
changeset: 346112:599ae91043dc
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Jun 26 07:31:35 2016 +0000

description:
Create a dedicated thread for the initial scsibus discovery instead
of using the completion thread. This prevents a deadlock when a
command fails during discovery which needs to be handled by the
completion thread.

diffstat:

 sys/dev/scsipi/scsiconf.c |  32 ++++++++++++++++++++++++++------
 1 files changed, 26 insertions(+), 6 deletions(-)

diffs (72 lines):

diff -r 880489c8692b -r 599ae91043dc sys/dev/scsipi/scsiconf.c
--- a/sys/dev/scsipi/scsiconf.c Sun Jun 26 07:22:15 2016 +0000
+++ b/sys/dev/scsipi/scsiconf.c Sun Jun 26 07:31:35 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: scsiconf.c,v 1.274 2016/05/02 19:18:29 christos Exp $  */
+/*     $NetBSD: scsiconf.c,v 1.275 2016/06/26 07:31:35 mlelstv Exp $   */
 
 /*-
  * Copyright (c) 1998, 1999, 2004 The NetBSD Foundation, Inc.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: scsiconf.c,v 1.274 2016/05/02 19:18:29 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: scsiconf.c,v 1.275 2016/06/26 07:31:35 mlelstv Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -121,7 +121,8 @@
 };
 
 static int     scsibusprint(void *, const char *);
-static void    scsibus_config(struct scsipi_channel *, void *);
+static void    scsibus_discover_thread(void *);
+static void    scsibus_config(struct scsibus_softc *);
 
 const struct scsipi_bustype scsi_bustype = {
        SCSIPI_BUSTYPE_BUSTYPE(SCSIPI_BUSTYPE_SCSI, SCSIPI_BUSTYPE_SCSI_PSCSI),
@@ -245,8 +246,8 @@
        RUN_ONCE(&scsi_conf_ctrl, scsibus_init);
 
        /* Initialize the channel structure first */
-       chan->chan_init_cb = scsibus_config;
-       chan->chan_init_cb_arg = sc;
+       chan->chan_init_cb = NULL;
+       chan->chan_init_cb_arg = NULL;
 
        scsi_initq = malloc(sizeof(struct scsi_initq), M_DEVBUF, M_WAITOK);
        scsi_initq->sc_channel = chan;
@@ -256,12 +257,31 @@
                aprint_error_dev(sc->sc_dev, "failed to init channel\n");
                return;
        }
+
+        /*
+         * Create the discover thread
+         */
+        if (kthread_create(PRI_NONE, 0, NULL, scsibus_discover_thread, sc,
+            NULL, "%s-d", chan->chan_name)) {
+                aprint_error_dev(sc->sc_dev, "unable to create discovery "
+                   "thread for channel %d\n", chan->chan_channel);
+                return;
+        }
 }
 
 static void
-scsibus_config(struct scsipi_channel *chan, void *arg)
+scsibus_discover_thread(void *arg)
 {
        struct scsibus_softc *sc = arg;
+
+       scsibus_config(sc);
+       kthread_exit(0);
+}
+
+static void
+scsibus_config(struct scsibus_softc *sc)
+{
+       struct scsipi_channel *chan = sc->sc_channel;
        struct scsi_initq *scsi_initq;
 
 #ifndef SCSI_DELAY