From owner-freebsd-usb@FreeBSD.ORG  Tue Dec 20 14:25:54 2011
Return-Path: <owner-freebsd-usb@FreeBSD.ORG>
Delivered-To: freebsd-usb@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 72BEE106564A
	for <freebsd-usb@freebsd.org>; Tue, 20 Dec 2011 14:25:54 +0000 (UTC)
	(envelope-from asmrookie@gmail.com)
Received: from mail-ww0-f50.google.com (mail-ww0-f50.google.com [74.125.82.50])
	by mx1.freebsd.org (Postfix) with ESMTP id 0B83A8FC15
	for <freebsd-usb@freebsd.org>; Tue, 20 Dec 2011 14:25:53 +0000 (UTC)
Received: by wgbdr11 with SMTP id dr11so12537122wgb.31
	for <freebsd-usb@freebsd.org>; Tue, 20 Dec 2011 06:25:53 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=mime-version:sender:in-reply-to:references:date
	:x-google-sender-auth:message-id:subject:from:to:cc:content-type
	:content-transfer-encoding;
	bh=WzZ8UZEsPNL2y3dL6ipucPAlaiKfVn6+bPyEa7fTrZg=;
	b=fVBBwEZ3eh7HqkuooLXPyK6gYCOUeWs6IQXcj1ihRKNce5Zy/Ey7PDwbVoOG1v5vjT
	nuH2Cjq0JbKzziegCwkIb2qPcmp4yiWZFk9mOqDnfqW1PSnADJeTODsFIknX/h248bau
	0JxlhtrO4pOJfGuBgaqbw059lRtQpVav3Whig=
MIME-Version: 1.0
Received: by 10.227.200.206 with SMTP id ex14mr2188715wbb.11.1324389604621;
	Tue, 20 Dec 2011 06:00:04 -0800 (PST)
Sender: asmrookie@gmail.com
Received: by 10.216.18.130 with HTTP; Tue, 20 Dec 2011 06:00:04 -0800 (PST)
In-Reply-To: <4EF088C8.8090906@FreeBSD.org>
References: <4EF088C8.8090906@FreeBSD.org>
Date: Tue, 20 Dec 2011 15:00:04 +0100
X-Google-Sender-Auth: XZ0Di2mgYVE60oLjD1BkrRdRi7A
Message-ID: <CAJ-FndC+U2XkxEA=k-_FjOk1mKqhafUUrxA8fo8KAfeN8QfNYg@mail.gmail.com>
From: Attilio Rao <attilio@freebsd.org>
To: Andriy Gapon <avg@freebsd.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: freebsd-usb@freebsd.org
Subject: Re: ukbd locking update
X-BeenThere: freebsd-usb@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: FreeBSD support for USB <freebsd-usb.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-usb>
List-Post: <mailto:freebsd-usb@freebsd.org>
List-Help: <mailto:freebsd-usb-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 20 Dec 2011 14:25:54 -0000

2011/12/20 Andriy Gapon <avg@freebsd.org>:
>
> I completing a patch that changes some locking in ukbd to account for
> SCHEDULER_STOPPED and for other realities of the code.
>
> As a preview I would like to share couple of observations that had their =
effect
> on the patch.
>
> 1. Acquiring Giant in device_attach, _detach in similar newbus method
> implementations should be redundant because those are already executed wi=
th
> Giant held. =C2=A0That's done either by the general newbus code or via
> usbd_enum_lock() when the operations are executed in the USB explore thre=
ad.

That's right, however, if you plan to axe those because of the newbus
assumption I'd prefer you add a comment for every function you touch
saying that it needs to be Giant protected (in order to cope with them
once newbus is made MPSAFE).

Attilio


--=20
Peace can only be achieved by understanding - A. Einstein