From 5d0fb0e6a13d29aab69eab8a3726d07f7ec9606b Mon Sep 17 00:00:00 2001
From: Michael Neumann <mneumann@dragonflybsd.org>
Date: Sun, 25 May 2008 16:53:41 +0000
Subject: [PATCH] Defer boot-time exploration of USB busses until all devices
 in the system have been attached, but no later. This ensures that we do not
 explore ohci or uhci busses before the companion ehci controller has been
 initialised, so it should fix the problem of multi-speed USB devices getting
 attached as USB 1 devices first and then re-attached as USB 2.

This fixes issue #946 for qemu and my HP Compaq 6710b laptop.

Obtained-from:  FreeBSD/usb.c 1.104 to 1.106 and NetBSD/usb.c 1.35
Dragonfly-bug:  <http://bugs.dragonflybsd.org/issue947>
---
 sys/bus/usb/usb.c | 43 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 11 deletions(-)

diff --git a/sys/bus/usb/usb.c b/sys/bus/usb/usb.c
index d1546fbcdd..4fb89e5a33 100644
--- a/sys/bus/usb/usb.c
+++ b/sys/bus/usb/usb.c
@@ -1,7 +1,7 @@
 /*
  * $NetBSD: usb.c,v 1.68 2002/02/20 20:30:12 christos Exp $
  * $FreeBSD: src/sys/dev/usb/usb.c,v 1.106 2005/03/27 15:31:23 iedowse Exp $
- * $DragonFly: src/sys/bus/usb/usb.c,v 1.43 2008/05/24 09:11:09 swildner Exp $
+ * $DragonFly: src/sys/bus/usb/usb.c,v 1.44 2008/05/25 16:53:41 mneumann Exp $
  */
 
 /* Also already merged from NetBSD:
@@ -117,6 +117,7 @@ int	usb_noexplore = 0;
 struct usb_softc {
 	device_t	sc_dev;		/* base device */
 	cdev_t		sc_usbdev;
+	TAILQ_ENTRY(usb_softc) sc_coldexplist; /* cold needs-explore list */
 	usbd_bus_handle sc_bus;		/* USB controller */
 	struct usbd_port sc_port;	/* dummy port for root hub */
 
@@ -156,7 +157,10 @@ static void	usb_task_thread(void *);
 
 static cdev_t usb_dev;		/* The /dev/usb device. */
 static int usb_ndevs;			/* Number of /dev/usbN devices. */
-
+/* Busses to explore at the end of boot-time device configuration */
+static TAILQ_HEAD(, usb_softc) usb_coldexplist =
+    TAILQ_HEAD_INITIALIZER(usb_coldexplist);
+ 
 #define USB_MAX_EVENTS 100
 struct usb_event_q {
 	struct usb_event ue;
@@ -245,11 +249,9 @@ usb_attach(device_t self)
 	}
 	kprintf("\n");
 
-#if 0
 	/* Make sure not to use tsleep() if we are cold booting. */
 	if (cold)
 		sc->sc_bus->use_polling++;
-#endif
 
 	ue.u.ue_ctrlr.ue_bus = device_get_unit(sc->sc_dev);
 	usb_add_event(USB_EVENT_CTRLR_ATTACH, &ue);
@@ -287,12 +289,12 @@ usb_attach(device_t self)
 		 * the keyboard will not work until after cold boot.
 		 */
 		if (cold) {
-			/*
-			 * XXX Exploring high speed device here will
-			 * hang the system.
-			 */
-			if (speed != USB_SPEED_HIGH)
+			/* Explore high-speed busses before others. */
+			if (speed == USB_SPEED_HIGH)
 				dev->hub->explore(sc->sc_bus->root_hub);
+			else
+				TAILQ_INSERT_TAIL(&usb_coldexplist, sc,
+				    sc_coldexplist);
 		}
 #endif
 	} else {
@@ -300,10 +302,8 @@ usb_attach(device_t self)
 		    "root hub problem, error=%d\n", err);
 		sc->sc_dying = 1;
 	}
-#if 0
 	if (cold)
 		sc->sc_bus->use_polling--;
-#endif
 
 	usb_create_event_thread(sc);
 	/* The per controller devices (used for usb_discover) */
@@ -922,6 +922,27 @@ usb_child_detached(device_t self, device_t child)
 	sc->sc_port.device = NULL;
 }
 
+/* Explore USB busses at the end of device configuration */
+static void
+usb_cold_explore(void *arg)
+{
+	struct usb_softc *sc;
+
+	KASSERT(cold || TAILQ_EMPTY(&usb_coldexplist),
+	    ("usb_cold_explore: busses to explore when !cold"));
+	while (!TAILQ_EMPTY(&usb_coldexplist)) {
+		sc = TAILQ_FIRST(&usb_coldexplist);
+		TAILQ_REMOVE(&usb_coldexplist, sc, sc_coldexplist);
+
+		sc->sc_bus->use_polling++;
+		sc->sc_port.device->hub->explore(sc->sc_bus->root_hub);
+		sc->sc_bus->use_polling--;
+	}
+}
+
+SYSINIT(usb_cold_explore, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
+    usb_cold_explore, NULL);
+
 DRIVER_MODULE(usb, ohci, usb_driver, usb_devclass, 0, 0);
 DRIVER_MODULE(usb, uhci, usb_driver, usb_devclass, 0, 0);
 DRIVER_MODULE(usb, ehci, usb_driver, usb_devclass, 0, 0);
-- 
2.11.4.GIT