Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753149Ab0AaSuo (ORCPT ); Sun, 31 Jan 2010 13:50:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752216Ab0AaSun (ORCPT ); Sun, 31 Jan 2010 13:50:43 -0500 Received: from mta5.srv.hcvlny.cv.net ([167.206.4.200]:40251 "EHLO mta5.srv.hcvlny.cv.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751404Ab0AaSum (ORCPT ); Sun, 31 Jan 2010 13:50:42 -0500 Date: Sun, 31 Jan 2010 13:50:33 -0500 From: Michael Breuer Subject: Re: [PATCH] sky2: receive dma mapping error handling In-reply-to: <4B650D53.2010607@majjas.com> To: Jarek Poplawski Cc: Stephen Hemminger , David Miller , akpm@linux-foundation.org, flyboy@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Michael Chan , Don Fry , Francois Romieu , Matt Carlson Message-id: <4B65D0F9.2020602@majjas.com> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7BIT References: <4B61ADF1.7060705@majjas.com> <4B61BEA4.1030905@majjas.com> <20100128090835.0d93e53a@nehalam> <4B61DB79.4080703@majjas.com> <20100128223447.GC3109@del.dom.local> <4B621316.8070308@majjas.com> <20100128225621.GD3109@del.dom.local> <4B6216B9.1010802@majjas.com> <20100128153643.0fca3c51@nehalam> <4B645EF4.4050701@majjas.com> <20100131003449.GA11935@del.dom.local> <4B650D53.2010607@majjas.com> User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.7) Gecko/20100111 Lightning/1.0b2pre Thunderbird/3.0.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1180 Lines: 32 On 1/30/2010 11:55 PM, Michael Breuer wrote: > On 01/30/2010 07:34 PM, Jarek Poplawski wrote: >> >> Could you try the patch below to show maybe some other users of >> dma-debug entries? >> >> Jarek P. >> --- >> > With the default # entries & dma_debug_driver=sky2: > > 6:00 is eth0 & 4:00 is eth1. > > Jan 30 23:53:14 mail kernel: DMA-API: 0000:06:00.0: entries: 31961 > ... > I put a printk as a third else case in sky2_tx_unmap. Looks like the issue is that a large number (perhaps all) calls to sky2_tx_unmap have re->flags set to neither TX_MAP_SINGLE or TX_MAP_PAGE. Thus the elements are never being unmapped. I suspect that the system collapses when using DMAR sooner than if not using DMAR. Probably some hardware limitation on the number of mapped elements that is less than the software limitation. I don't see at present how a ring element can ever get to this code without re->flags being set to one or the other. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/