[src/trunk]: src/sys/dev/usb usb task fixes, from jared and myself:

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

details:   https://anonhg.NetBSD.org/src/rev/a6b66bfb9a8a
branches:  trunk
changeset: 780318:a6b66bfb9a8a
user:      mrg <mrg%NetBSD.org@localhost>
date:      Fri Jul 20 07:31:14 2012 +0000

description:
usb task fixes, from jared and myself:

- create the task/event threads in usb_attach() so they're more likely
  to be ready when usb_doattach() runs

- move the task thread creation into usb_once_init(), instead of having
  some other method of only creating them once

diffstat:

 sys/dev/usb/usb.c |  66 ++++++++++++++++++++++++++++--------------------------
 1 files changed, 34 insertions(+), 32 deletions(-)

diffs (161 lines):

diff -r 72f83eba369c -r a6b66bfb9a8a sys/dev/usb/usb.c
--- a/sys/dev/usb/usb.c Fri Jul 20 04:13:28 2012 +0000
+++ b/sys/dev/usb/usb.c Fri Jul 20 07:31:14 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usb.c,v 1.133 2012/07/20 02:23:35 christos Exp $       */
+/*     $NetBSD: usb.c,v 1.134 2012/07/20 07:31:14 mrg Exp $    */
 
 /*
  * Copyright (c) 1998, 2002, 2008, 2012 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.133 2012/07/20 02:23:35 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.134 2012/07/20 07:31:14 mrg Exp $");
 
 #include "opt_compat_netbsd.h"
 #include "opt_usb.h"
@@ -104,7 +104,6 @@
        kcondvar_t cv;
        struct lwp *task_thread_lwp;
        const char *name;
-       int taskcreated;        /* task thread exists. */
 };
 
 static struct usb_taskq usb_taskq[USB_NUM_TASKQS];
@@ -167,6 +166,8 @@
     usb_match, usb_attach, usb_detach, usb_activate, NULL, usb_childdet,
     DVF_DETACH_SHUTDOWN);
 
+static const char *taskq_names[] = USB_TASKQ_NAMES;
+
 int
 usb_match(device_t parent, cfdata_t match, void *aux)
 {
@@ -179,9 +180,11 @@
 {
        static ONCE_DECL(init_control);
        struct usb_softc *sc = device_private(self);
+       bool mpsafe;
        int usbrev;
 
        sc->sc_bus = aux;
+       mpsafe = sc->sc_bus->methods->get_lock ? true : false;
        usbrev = sc->sc_bus->usbrev;
 
        aprint_naive("\n");
@@ -198,6 +201,12 @@
        }
        aprint_normal("\n");
 
+       if (mpsafe)
+               sc->sc_bus->methods->get_lock(sc->sc_bus, &sc->sc_bus->lock);
+       else
+               sc->sc_bus->lock = NULL;
+       usb_create_event_thread(self);
+
        RUN_ONCE(&init_control, usb_once_init);
        config_interrupts(self, usb_doattach);
 }
@@ -205,10 +214,31 @@
 static int
 usb_once_init(void)
 {
+       struct usb_taskq *taskq;
+       int i;
 
        selinit(&usb_selevent);
        mutex_init(&usb_event_lock, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&usb_event_cv, "usbrea");
+
+       for (i = 0; i < USB_NUM_TASKQS; i++) {
+               taskq = &usb_taskq[i];
+
+               TAILQ_INIT(&taskq->tasks);
+               mutex_init(&taskq->lock, MUTEX_DEFAULT, IPL_NONE);
+               cv_init(&taskq->cv, "usbtsk");
+               taskq->name = taskq_names[i];
+               if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
+                   usb_task_thread, taskq, &taskq->task_thread_lwp,
+                   "%s", taskq->name)) {
+                       printf("unable to create task thread: %s\n", taskq->name);
+                       panic("usb_create_event_thread task");
+               }
+               /*
+                * XXX we should make sure these threads are alive before
+                * end up using them in usb_doattach().
+                */
+       }
        return 0;
 }
 
@@ -220,7 +250,7 @@
        usbd_status err;
        int speed;
        struct usb_event *ue;
-       bool mpsafe = sc->sc_bus->methods->get_lock ? true : false;
+       const bool mpsafe = sc->sc_bus->methods->get_lock ? true : false;
 
        DPRINTF(("usbd_doattach\n"));
 
@@ -239,11 +269,6 @@
                panic("usb_doattach");
        }
 
-       if (mpsafe) {
-               sc->sc_bus->methods->get_lock(sc->sc_bus, &sc->sc_bus->lock);
-       } else {
-               sc->sc_bus->lock = NULL;
-       }
        cv_init(&sc->sc_bus->needs_explore_cv, "usbevt");
 
        ue = usb_alloc_event();
@@ -288,7 +313,6 @@
        }
 
        config_pending_incr();
-       usb_create_event_thread(self);
 
        if (!pmf_device_register(self, NULL, NULL))
                aprint_error_dev(self, "couldn't establish power handler\n");
@@ -299,14 +323,10 @@
        return;
 }
 
-static const char *taskq_names[] = USB_TASKQ_NAMES;
-
 void
 usb_create_event_thread(device_t self)
 {
        struct usb_softc *sc = device_private(self);
-       struct usb_taskq *taskq;
-       int i;
 
        if (kthread_create(PRI_NONE,
            sc->sc_bus->lock ? KTHREAD_MPSAFE : 0, NULL,
@@ -316,24 +336,6 @@
                       device_xname(self));
                panic("usb_create_event_thread");
        }
-       for (i = 0; i < USB_NUM_TASKQS; i++) {
-               taskq = &usb_taskq[i];
-
-               if (taskq->taskcreated)
-                       continue;
-
-               TAILQ_INIT(&taskq->tasks);
-               mutex_init(&taskq->lock, MUTEX_DEFAULT, IPL_NONE);
-               cv_init(&taskq->cv, "usbtsk");
-               taskq->taskcreated = 1;
-               taskq->name = taskq_names[i];
-               if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
-                   usb_task_thread, taskq, &taskq->task_thread_lwp,
-                   "%s", taskq->name)) {
-                       printf("unable to create task thread: %s\n", taskq->name);
-                       panic("usb_create_event_thread task");
-               }
-       }
 }
 
 /*