From owner-cvs-src@FreeBSD.ORG Wed May 7 20:21:38 2008 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2CE571065670; Wed, 7 May 2008 20:21:38 +0000 (UTC) (envelope-from marius@alchemy.franken.de) Received: from alchemy.franken.de (alchemy.franken.de [194.94.249.214]) by mx1.freebsd.org (Postfix) with ESMTP id B07AB8FC13; Wed, 7 May 2008 20:21:37 +0000 (UTC) (envelope-from marius@alchemy.franken.de) Received: from alchemy.franken.de (localhost [127.0.0.1]) by alchemy.franken.de (8.14.1/8.14.1/ALCHEMY.FRANKEN.DE) with ESMTP id m47KLZUE024731; Wed, 7 May 2008 22:21:36 +0200 (CEST) (envelope-from marius@alchemy.franken.de) Received: (from marius@localhost) by alchemy.franken.de (8.14.1/8.14.1/Submit) id m47KLZPG024730; Wed, 7 May 2008 22:21:35 +0200 (CEST) (envelope-from marius) Date: Wed, 7 May 2008 22:21:35 +0200 From: Marius Strobl To: Sam Leffler Message-ID: <20080507202135.GA65358@alchemy.franken.de> References: <200803201619.m2KGJQr7033985@repoman.freebsd.org> <20080412193358.GA44768@alchemy.franken.de> <20080423203622.GA66545@alchemy.franken.de> <480F9F8B.5050209@freebsd.org> <20080423205943.GG99566@alchemy.franken.de> <480FA41F.20407@freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <480FA41F.20407@freebsd.org> User-Agent: Mutt/1.4.2.3i Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/dev/usb ehci.c ohci.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 May 2008 20:21:38 -0000 On Wed, Apr 23, 2008 at 02:03:27PM -0700, Sam Leffler wrote: > Marius Strobl wrote: > >On Wed, Apr 23, 2008 at 01:43:55PM -0700, Sam Leffler wrote: > > > >>Marius Strobl wrote: > >> > >>>On Sat, Apr 12, 2008 at 09:33:58PM +0200, Marius Strobl wrote: > >>> > >>> > >>>>On Thu, Mar 20, 2008 at 04:19:26PM +0000, Sam Leffler wrote: > >>>> > >>>> > >>>>>sam 2008-03-20 16:19:25 UTC > >>>>> > >>>>> FreeBSD src repository > >>>>> > >>>>> Modified files: > >>>>> sys/dev/usb ehci.c ohci.c > >>>>> Log: > >>>>> Workaround design botch in usb: blindly mixing bus_dma with PIO does > >>>>> not > >>>>> work on architectures with a write-back cache as the PIO writes end up > >>>>> in the cache which the sync(BUS_DMASYNC_POSTREAD) in > >>>>> usb_transfer_complete > >>>>> then discards; compensate in the xfer methods that do PIO by pushing > >>>>> the > >>>>> writes out of the cache before usb_transfer_complete is called. > >>>>> > >>>>> This fixes USB on xscale and likely other places. > >>>>> > >>>>> Sponsored by: hobnob > >>>>> Reviewed by: cognet, imp > >>>>> MFC after: 1 month > >>>>> > >>>>> Revision Changes Path > >>>>> 1.62 +16 -0 src/sys/dev/usb/ehci.c > >>>>> 1.171 +16 -0 src/sys/dev/usb/ohci.c > >>>>> > >>>>> > >>>>This causes a crash during boot on sparc64. Looks like map is still > >>>>NULL at that point. > >>>> > >>>> > >>>> > >>>Are you ok with the change below or would that also prevent > >>>your kludge from taking effect? > >>> > >>>Marius > >>> > >>>Index: ehci.c > >>>=================================================================== > >>>RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ehci.c,v > >>>retrieving revision 1.62 > >>>diff -u -r1.62 ehci.c > >>>--- ehci.c 20 Mar 2008 16:19:25 -0000 1.62 > >>>+++ ehci.c 23 Apr 2008 20:23:58 -0000 > >>>@@ -664,6 +664,8 @@ > >>> usbd_pipe_handle pipe = xfer->pipe; > >>> bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag; > >>> struct usb_dma_mapping *dmap = &xfer->dmamap; > >>>+ if (dmap->map == NULL) > >>>+ return; > >>> bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE); > >>>} > >>> > >>>Index: ohci.c > >>>=================================================================== > >>>RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ohci.c,v > >>>retrieving revision 1.171 > >>>diff -u -r1.171 ohci.c > >>>--- ohci.c 20 Mar 2008 16:19:25 -0000 1.171 > >>>+++ ohci.c 21 Apr 2008 19:13:54 -0000 > >>>@@ -1571,6 +1571,8 @@ > >>> usbd_pipe_handle pipe = xfer->pipe; > >>> bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag; > >>> struct usb_dma_mapping *dmap = &xfer->dmamap; > >>>+ if (dmap->map == NULL) > >>>+ return; > >>> bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE); > >>>} > >>> > >>> > >>> > >>> > >>> > >>You have not identified why you don't have a dma map. I don't have a > >>way to diagnose your problem and so far as I know no other platform had > >>an issue w/ the change. I suggest you figure out why your map is not > >>setup instead of adding a hack. > >> > >> > > > >It's because the usb(4) code doesn't create DMA maps for > >zero-length transfers, see usbd_transfer(). In the case of > >the backtrace I posted not for usbd_set_address(), which > >does USETW(req.wLength, 0) so later on size is 0 in > >usbd_transfer() hence no DMA map. I don't know why your > >hack doesn't also crash other platforms. > > > Thanks for explaining, I will look. Please hold off for a bit. > Style-wise the version below probably is more appropriate than the above one. The question still is whether that fix prevents hacksync() taking effect as desired, which would make it a very evil hack though as hacksync() then relies on bus_dmamap_sync() working on uninitialized DMA maps. Marius Index: ehci.c =================================================================== RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ehci.c,v retrieving revision 1.62 diff -u -p -r1.62 ehci.c --- ehci.c 20 Mar 2008 16:19:25 -0000 1.62 +++ ehci.c 27 Apr 2008 14:09:53 -0000 @@ -661,9 +661,13 @@ ehci_pcd_enable(void *v_sc) static __inline void hacksync(usbd_xfer_handle xfer) { - usbd_pipe_handle pipe = xfer->pipe; - bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag; - struct usb_dma_mapping *dmap = &xfer->dmamap; + bus_dma_tag_t tag; + struct usb_dma_mapping *dmap; + + if (xfer->length == 0) + return; + tag = xfer->pipe->device->bus->buffer_dmatag; + dmap = &xfer->dmamap; bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE); } Index: ohci.c =================================================================== RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ohci.c,v retrieving revision 1.171 diff -u -p -r1.171 ohci.c --- ohci.c 20 Mar 2008 16:19:25 -0000 1.171 +++ ohci.c 27 Apr 2008 14:09:37 -0000 @@ -1568,9 +1568,13 @@ ohci_device_bulk_done(usbd_xfer_handle x static __inline void hacksync(usbd_xfer_handle xfer) { - usbd_pipe_handle pipe = xfer->pipe; - bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag; - struct usb_dma_mapping *dmap = &xfer->dmamap; + bus_dma_tag_t tag; + struct usb_dma_mapping *dmap; + + if (xfer->length == 0) + return; + tag = xfer->pipe->device->bus->buffer_dmatag; + dmap = &xfer->dmamap; bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE); }