From owner-freebsd-multimedia@FreeBSD.ORG Mon Mar 7 02:58:10 2005 Return-Path: Delivered-To: freebsd-multimedia@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BE25716A4CE for ; Mon, 7 Mar 2005 02:58:10 +0000 (GMT) Received: from ns.kt-is.co.kr (ns.kt-is.co.kr [211.218.149.125]) by mx1.FreeBSD.org (Postfix) with ESMTP id 099D843D53 for ; Mon, 7 Mar 2005 02:58:10 +0000 (GMT) (envelope-from yongari@kt-is.co.kr) Received: from michelle.kt-is.co.kr (ns2.kt-is.co.kr [220.76.118.193]) (authenticated bits=128) by ns.kt-is.co.kr (8.12.10/8.12.10) with ESMTP id j272s9Ah001821 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Mon, 7 Mar 2005 11:54:10 +0900 (KST) Received: from michelle.kt-is.co.kr (localhost.kt-is.co.kr [127.0.0.1]) by michelle.kt-is.co.kr (8.13.1/8.13.1) with ESMTP id j272vp1G001046 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 7 Mar 2005 11:57:51 +0900 (KST) (envelope-from yongari@kt-is.co.kr) Received: (from yongari@localhost) by michelle.kt-is.co.kr (8.13.1/8.13.1/Submit) id j272vggI001045; Mon, 7 Mar 2005 11:57:42 +0900 (KST) (envelope-from yongari@kt-is.co.kr) Date: Mon, 7 Mar 2005 11:57:42 +0900 From: Pyun YongHyeon To: Mathew Kanner Message-ID: <20050307025742.GA951@kt-is.co.kr> References: <20050305224005.GC4237@cnd.mcgill.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050305224005.GC4237@cnd.mcgill.ca> User-Agent: Mutt/1.4.2.1i X-Filter-Version: 1.11a (ns.kt-is.co.kr) cc: freebsd-multimedia@freebsd.org Subject: Re: uaudio patch, configurable buffer size X-BeenThere: freebsd-multimedia@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: yongari@kt-is.co.kr List-Id: Multimedia discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Mar 2005 02:58:10 -0000 On Sat, Mar 05, 2005 at 05:40:05PM -0500, Mathew Kanner wrote: > Hi All, > I couldn't use my usb device because the default buffer size > (16*1024 bytes) was too much to be allocated (dma changes that > happened a while ago). The following is a patch to make it a tunable: > > http://www.cnd.mcgill.ca/~mat/uaudio-HEAD-buffersize-tunable.diff.gz > Hi Mathew, I guess the real reason DMA buffer allocation failure comes from the fixed argument 0x3fff of bus_dma_tag_create(9). And if we allow TUNABLE for "hw.snd.uaudio.default_buffer_size" we should also update the argument of bus_dma_tag_create(9) too or we couldn't allocate larger buffer size than 16383(0x3fff). Another thing to note is that we are not allowed to use buffer size less than 4KB since we use bufsz = pcm_getbuffersize(dev, 4096, UAUDIO_PCM_BUFF_SIZE, 65536); in uaudio_pcm.c. So I think you should also reject size less than 4KB. -- Regards, Pyun YongHyeon http://www.kr.freebsd.org/~yongari | yongari@freebsd.org