From owner-freebsd-questions@FreeBSD.ORG  Sat Oct 14 23:50:05 2006
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
X-Original-To: freebsd-questions@freebsd.org
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id AEF8F16A403
	for <freebsd-questions@freebsd.org>;
	Sat, 14 Oct 2006 23:50:05 +0000 (UTC)
	(envelope-from wmoran@collaborativefusion.com)
Received: from mx00.pub.collaborativefusion.com
	(mx00.pub.collaborativefusion.com [206.210.89.199])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 3695B43D49
	for <freebsd-questions@freebsd.org>;
	Sat, 14 Oct 2006 23:50:04 +0000 (GMT)
	(envelope-from wmoran@collaborativefusion.com)
Received: from localhost (c-71-60-174-60.hsd1.pa.comcast.net [71.60.174.60])
	(AUTH: LOGIN wmoran, TLS: TLSv1/SSLv3,256bits,AES256-SHA)
	by wingspan with esmtp; Sat, 14 Oct 2006 19:50:03 -0400
	id 00056403.453177AC.00013F4E
Date: Sat, 14 Oct 2006 19:50:02 -0400
From: Bill Moran <wmoran@collaborativefusion.com>
To: usleepless@gmail.com
Message-Id: <20061014195002.8dfb46ac.wmoran@collaborativefusion.com>
In-Reply-To: <c39ec84c0610141332q7abf9220q8b2715f33a72e58b@mail.gmail.com>
References: <c39ec84c0610141332q7abf9220q8b2715f33a72e58b@mail.gmail.com>
Organization: Collaborative Fusion
X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.20; i386-portbld-freebsd6.1)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: freebsd-questions@freebsd.org
Subject: Re: Removing Giant from a driver
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 14 Oct 2006 23:50:05 -0000


You might do better by subscribing to hackers@ and posting there.

This question is a little more technical than this list usually deals
with.

usleepless@gmail.com wrote:
> Hi All,
> 
> i have been tweaking the pvr250 driver to support pvr150s/500s. now i
> want to remove Giant from the code.
> 
> problem is, i am not sure what to do. i have created a mutex which
> replaces the spltty and splx calls. but this crashes my box :-)
> 
> the original code looks like this:
>         /*
>          * Allocate a DMA tag for the scatter / gather list.
>          */
>         error = bus_dma_tag_create(sc->parent_dmat, 1, 0,
>                                    BUS_SPACE_MAXADDR_32BIT,
>                                    BUS_SPACE_MAXADDR, NULL, NULL,
>                                    CXM_SG_BUFFERS
>                                    * sizeof(struct cxm_sg_entry), 1,
>                                    BUS_SPACE_MAXSIZE_32BIT, 0,
> #if __FreeBSD_version >= 501102
>                                    busdma_lock_mutex, &Giant,
> #endif
>                                    &sc->enc_sg.dmat);
> 
> what should it look like?
> 
> and how will i prevent the interrupt routine from interfering with
> userland operations? can i place a "mtx_lock()" call in the interrupt
> routine?
> 
> is there a howto somewhere?
> 
> regards,
> 
> usleep
> _______________________________________________
> freebsd-questions@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"


-- 
Bill Moran

Many miles away, something crawls through the slime at the bottom of a
dark, Scottish lake.