From owner-freebsd-current@FreeBSD.ORG Fri Nov 7 17:09:23 2008 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 9BF1B1065678 for ; Fri, 7 Nov 2008 17:09:23 +0000 (UTC) (envelope-from hselasky@c2i.net) Received: from swip.net (mailfe08.swip.net [212.247.154.225]) by mx1.freebsd.org (Postfix) with ESMTP id D3AB68FC24 for ; Fri, 7 Nov 2008 17:09:22 +0000 (UTC) (envelope-from hselasky@c2i.net) X-Cloudmark-Score: 0.000000 [] X-Cloudmark-Analysis: v=1.0 c=1 a=J1zRX2_4DjwA:10 a=xw72rLtdcjMA:10 a=d6BVkb5LuPPVEe4iNQMLyA==:17 a=6I5d2MoRAAAA:8 a=3YTIT_jGPHLJczaYVB8A:9 a=RF4BB6zLHrelT4Av70wA:7 a=8OqP3KE3YxgjblQQsK1AduliE-QA:4 a=LY0hPdMaydYA:10 Received: from [62.113.135.6] (account mc467741@c2i.net [62.113.135.6] verified) by mailfe08.swip.net (CommuniGate Pro SMTP 5.2.6) with ESMTPA id 1142216797; Fri, 07 Nov 2008 18:09:21 +0100 From: Hans Petter Selasky To: freebsd-current@freebsd.org Date: Fri, 7 Nov 2008 18:11:26 +0100 User-Agent: KMail/1.9.7 References: <20081107082740.GA1334@icarus.home.lan> In-Reply-To: <20081107082740.GA1334@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200811071811.27181.hselasky@c2i.net> Cc: Jeremy Chadwick Subject: Re: Kernel panic when copying data to umass device (USB4BSD) - problem found 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: Fri, 07 Nov 2008 17:09:23 -0000 On Friday 07 November 2008, Jeremy Chadwick wrote: > Not sure if this is caused by problems with USB4BSD or not, as I can > reproduce it on RELENG_7 (but there, the kernel does not panic; it just > "wedges" in a loop/thread somewhere; SSH sessions remain up, but > commands running stop; hitting Ctrl-T shows them in all sorts of > different states, but the states never change; hitting Ctrl-Alt-Esc does > in fact drop me to db>). > Hi Jeremy, I've reproduced the issue with some mods to the usb2_busdma.c on 32-bit arcitecture and have made a fix for this problem. Try the following patch and re-test! Some mem-stick benchmarks would be nice ... My private SVN also has this patch in addition to P4. --HPS http://perforce.freebsd.org/chv.cgi?CH=152624 Fix some problems related to busdma: Need to unload DMA maps before re-use! Fix a corner case when loading zero bytes. Affected files ... .. //depot/projects/usb/src/sys/dev/usb2/core/usb2_busdma.c#10 edit Differences ... ==== //depot/projects/usb/src/sys/dev/usb2/core/usb2_busdma.c#10 (text+ko) ==== @@ -597,6 +597,12 @@ uptag = pc->tag_parent; /* + * We have to unload the previous loaded DMA + * pages before trying to load a new one! + */ + bus_dmamap_unload(pc->tag, pc->map); + + /* * Try to load memory into DMA. */ err = bus_dmamap_load( @@ -612,6 +618,12 @@ } else { /* + * We have to unload the previous loaded DMA + * pages before trying to load a new one! + */ + bus_dmamap_unload(pc->tag, pc->map); + + /* * Try to load memory into DMA. The callback * will be called in all cases: */ @@ -639,6 +651,10 @@ void usb2_pc_cpu_invalidate(struct usb2_page_cache *pc) { + if (pc->page_offset_end == pc->page_offset_buf) { + /* nothing has been loaded into this page cache! */ + return; + } bus_dmamap_sync(pc->tag, pc->map, BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD); return; @@ -650,6 +666,10 @@ void usb2_pc_cpu_flush(struct usb2_page_cache *pc) { + if (pc->page_offset_end == pc->page_offset_buf) { + /* nothing has been loaded into this page cache! */ + return; + } bus_dmamap_sync(pc->tag, pc->map, BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD); return; @@ -953,6 +973,12 @@ if (size > 0) { + /* + * We have to unload the previous loaded DMA + * pages before trying to load a new one! + */ + bus_dmamap_unload(pc->tag, pc->map); + /* try to load memory into DMA using using no wait option */ if (bus_dmamap_load(pc->tag, pc->map, pc->buffer, size, NULL, BUS_DMA_NOWAIT)) { @@ -990,6 +1016,10 @@ len = pc->page_offset_end - pc->page_offset_buf; + if (len == 0) { + /* nothing has been loaded into this page cache */ + return; + } bus_dmamap_sync(pc->tag, pc->map, 0, len, BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD); return; @@ -1005,6 +1035,10 @@ len = pc->page_offset_end - pc->page_offset_buf; + if (len == 0) { + /* nothing has been loaded into this page cache */ + return; + } bus_dmamap_sync(pc->tag, pc->map, 0, len, BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD); return;