From owner-freebsd-current@FreeBSD.ORG Sun Dec 6 17:33:21 2009 Return-Path: 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 E28301065676 for ; Sun, 6 Dec 2009 17:33:21 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 656818FC17 for ; Sun, 6 Dec 2009 17:33:21 +0000 (UTC) Received: by bwz5 with SMTP id 5so2973505bwz.3 for ; Sun, 06 Dec 2009 09:33:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=/n1GyN86eRHmp+I5ou0xzpuS8vVar7bg0DyGc6ID14U=; b=bqjNfrrtRTWTuM9PCmUiskxhVOWIRsbI9jeuIlG3FAIRsU7hTz+nuiTPFGtAN9L1B+ AalMEMS7mqOEULi/hH21eDGon73kC1XhaAfdn0DWpuoixaSxMUWyEultj2u7ByRWH/tv MB/3ZfDbsfU424u1dvfPi4kcerJzMzR1uTKxw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=dPqXKOuMt8QJqxLOMyeoznOi2kT0lWXTa10alIRcU8CcQrJFyw5Qi95rJawP+0dQ7q 1KsBuSnz6+n5JRYYYhQVeZOjuZzJZbG+YqCm71Vs/K5dmSNG6vBbgLNpz5IR34Ln1242 SD7gaf5eLUmDtEH0C2YovjwMqieh09YT+V61w= Received: by 10.204.48.202 with SMTP id s10mr2357239bkf.106.1260120799149; Sun, 06 Dec 2009 09:33:19 -0800 (PST) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id 13sm1697654fxm.1.2009.12.06.09.33.18 (version=SSLv3 cipher=RC4-MD5); Sun, 06 Dec 2009 09:33:18 -0800 (PST) Sender: Alexander Motin Message-ID: <4B1BEADB.5090803@FreeBSD.org> Date: Sun, 06 Dec 2009 19:33:15 +0200 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20090901) MIME-Version: 1.0 To: Alexander Best References: In-Reply-To: X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-current@freebsd.org Subject: Re: Testing CAM wrapper for ata(4) controller drivers X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Dec 2009 17:33:22 -0000 Alexander Best wrote: > i've stumbled over a problem with ATA_CAM. when i accessing my dvd-drive i'm > not able to access any other cam members (ada* e.g.). > > when i issue the following command: > > `cdrecord dev=2,1,0 blank=all' > > binaries such as ls, top or vmstat simply stall until cdrecord finishes. > > this is the output of `camcontrol devlist -v': > > scbus2 on ata2 bus 0: > at scbus2 target 0 lun 0 (ada0,pass0) > at scbus2 target 1 lun 0 (pass1,cd0) > <> at scbus2 target -1 lun -1 () It was always bad idea to put CD and disk, which need to be used simultaneously, to the same PATA channel. PATA channel can execute only one command at a time, without using special technique, named overlap (part of TCQ), which is usually not supported by devices. When your blank command occupied CD, disk became inaccessible, until it complete. -- Alexander Motin