From owner-p4-projects@FreeBSD.ORG Fri Jan 19 18:42:20 2007 Return-Path: X-Original-To: p4-projects@freebsd.org Delivered-To: p4-projects@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 32767) id 5066E16A401; Fri, 19 Jan 2007 18:42:20 +0000 (UTC) X-Original-To: perforce@freebsd.org Delivered-To: perforce@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DA29616A404 for ; Fri, 19 Jan 2007 18:42:19 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.190]) by mx1.freebsd.org (Postfix) with ESMTP id 7328713C43E for ; Fri, 19 Jan 2007 18:42:19 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by nf-out-0910.google.com with SMTP id k27so545695nfc for ; Fri, 19 Jan 2007 10:42:18 -0800 (PST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=JA0JZMS2rvKTHVwyxHIoZ+4VK4FHxmpBAhcXzBYyNn0bPO31/x2T5tuLi6MUCQRNrne2e9rUvUnb0ow5ph/dQpy4++9hwL2145VdeDJt1MvsZENfEeoqmkKEpeWBzoPB3obPVSMBCOd++VfyQ2UpxGUbj48d1z9A3qAUzENvsTM= Received: by 10.49.36.6 with SMTP id o6mr2600091nfj.1169232134902; Fri, 19 Jan 2007 10:42:14 -0800 (PST) Received: by 10.48.238.14 with HTTP; Fri, 19 Jan 2007 10:42:14 -0800 (PST) Message-ID: <3bbf2fe10701191042i2833731an96c286c40877353@mail.gmail.com> Date: Fri, 19 Jan 2007 19:42:14 +0100 From: "Attilio Rao" Sender: asmrookie@gmail.com To: "Hans Petter Selasky" In-Reply-To: <200701191814.04201.hselasky@c2i.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200701191656.l0JGuPu7025321@repoman.freebsd.org> <3bbf2fe10701190858v4fbdf5ct5fd39c6e16f2a10d@mail.gmail.com> <200701191814.04201.hselasky@c2i.net> X-Google-Sender-Auth: f06d7ce540acef9d Cc: perforce@freebsd.org Subject: Re: PERFORCE change 113164 for review X-BeenThere: p4-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: p4 projects tree changes List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Jan 2007 18:42:20 -0000 2007/1/19, Hans Petter Selasky : > On Friday 19 January 2007 17:58, Attilio Rao wrote: > > 2007/1/19, Hans Petter Selasky : > > > http://perforce.freebsd.org/chv.cgi?CH=113164 > > > > > > Change 113164 by hselasky@hselasky_mini_itx on 2007/01/19 16:56:15 > > > > > > The sound mutex needs to allow recursion, else the > > > new "uaudio" will not work. > > > > > > Affected files ... > > > > > > .. //depot/projects/usb/src/sys/dev/sound/pcm/sound.c#3 edit > > > > > > Differences ... > > > > > > ==== //depot/projects/usb/src/sys/dev/sound/pcm/sound.c#3 (text+ko) ==== > > > > > > @@ -78,7 +78,7 @@ > > > m = malloc(sizeof(*m), M_DEVBUF, M_WAITOK | M_ZERO); > > > if (m == NULL) > > > return NULL; > > > - mtx_init(m, desc, type, MTX_DEF); > > > + mtx_init(m, desc, type, MTX_DEF|MTX_RECURSE); > > > return m; > > > #else > > > return (void *)0xcafebabe; > > > > Recursed mutexes very often are symptomatic of some some bug... > > it is the case? why the mutex is recursed? > > > > Because my system shares the lock with the "pcm channel" of the sound system. > That means it uses "c->lock" (see below) to protect the isochronous USB > transfers. The problem is that my USB callback calls "chn_intr()" which also > locks the same lock. > > Maybe this should be addressed by Ariff A. ? > > void > chn_intr(struct pcm_channel *c) > { > CHN_LOCK(c); > c->interrupts++; > if (c->direction == PCMDIR_PLAY) > chn_wrintr(c); > else > chn_rdintr(c); > CHN_UNLOCK(c); > } One solution can be taking off the calls CHN_LOCK/CHN_UNLOCK from the "internal" functions and checking with mtx_assert inside them. Attilio -- Peace can only be achieved by understanding - A. Einstein