From owner-freebsd-current@FreeBSD.ORG  Sat Oct  3 07:52:31 2009
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id E19C21065676
	for <freebsd-current@freebsd.org>; Sat,  3 Oct 2009 07:52:31 +0000 (UTC)
	(envelope-from hselasky@c2i.net)
Received: from swip.net (mailfe05.swip.net [212.247.154.129])
	by mx1.freebsd.org (Postfix) with ESMTP id 773AE8FC0A
	for <freebsd-current@freebsd.org>; Sat,  3 Oct 2009 07:52:31 +0000 (UTC)
X-Cloudmark-Score: 0.000000 []
X-Cloudmark-Analysis: v=1.0 c=1 a=aQey1_VUwUUA:10
	a=RERtC8nhXGhYvIZhK0yWrQ==:17 a=XxDeWrsLWpFRxdEFReUA:9
	a=O3vr-6xOhxxg5fUnN7EA:7 a=xP-kcI-DwXktOvvZSUfYx4ND2xQA:4
Received: from [90.149.203.35] (account mc467741@c2i.net HELO
	laptop.adsl.tele2.no)
	by mailfe05.swip.net (CommuniGate Pro SMTP 5.2.16)
	with ESMTPA id 1214505543; Sat, 03 Oct 2009 09:52:29 +0200
From: Hans Petter Selasky <hselasky@c2i.net>
To: freebsd-current@freebsd.org
Date: Sat, 3 Oct 2009 09:53:16 +0200
User-Agent: KMail/1.11.4 (FreeBSD/9.0-CURRENT; KDE/4.2.4; i386; ; )
References: <20091002150931.K35591@pooker.samsco.org>
In-Reply-To: <20091002150931.K35591@pooker.samsco.org>
X-Face: (%<A9p'; 5>:6u[ldzJ`0qjD7sCkfdMmD*RxpO<Q0yAl~?`'F?jDVb]E6TQ7'#h-VlLs}k/
	(yxg(p!IL.`#ng"%`BMrham7%UK,}VH\wUOm=^>wEEQ+KWt[{J#x6ow~JO:,zwp.(t; @Aq
	:4:&nFCgDb8[3oIeTb^'",;u{5{}C9>"PuY\)!=#\u9SSM-nz8+SR~B\!qBv
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200910030953.17359.hselasky@c2i.net>
Cc: 
Subject: Re: [PATCH] Fix for USB media not found at boot
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 03 Oct 2009 07:52:32 -0000

On Friday 02 October 2009 23:11:21 Scott Long wrote:
> All,
>
> I have a candidate patch to fix the problem with USB boot media not being
> found in time at boot, leading to the "mountroot" prompt instead of a
> booting system.  Please apply both patches below and let me know if it
> works for you.

Hi,

Your patch looks OK. Some checkpoints however:

Does your patch work if ehci/ohci/uhci is kldloaded after system startup?

Does your patch work if CAM is not in the kernel?

I have a simple imporovement to your patch:

I would just add a synchronously blocking call to the end of "usb_bus_attach".

Something like:

#ifdef USB_HAVE_CAM
static void
usb_cam_wait_cb(void *arg)
{
	struct usb_bus *bus = *(struct usb_bus **)arg;

    USB_BUS_LOCK(bus);
    *(struct usb_bus **)arg = NULL;
	wakeup(arg);
    USB_BUS_UNLOCK(bus);
}

static void
usb_wait_cam(struct usb_bus *bus)
{
    struct intr_config_hook *hook;
    void *temp = bus;
    hook = malloc(sizeof(*hook), M_TEMP, M_ZERO);
    hook->ich_func = usb_wait_cam_cb;
    hook->ich_arg = &temp;

	config_intrhook_establish(hook);

    USB_BUS_LOCK(bus);
    if (temp != NULL)
		mtx_sleep(&temp, &bus->bus_mtx, 0, "WCAM", 0);
    USB_BUS_UNLOCK(bus);
}
#endif

That way makes the code more simple and avoids a race with the CAM callback 
being called after that the hardware is detached. For example if the Host 
Controller resides on a removable device.

There are some more USB_HAVE_XXX in sys/dev/usb/usb_freebsd.h .

--HPS