From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH net] skge: dma_sync the whole receive buffer Date: Thu, 15 Aug 2013 08:41:17 -0700 Message-ID: <20130815084117.2f48fc58@nehalam.linuxnetplumber.net> References: <20130810104100.0ae20aa6@nehalam.linuxnetplumber.net> <20130810.132935.1257046025460198490.davem@davemloft.net> <20130810150207.37432299@nehalam.linuxnetplumber.net> <20130813.150955.1471100759610399160.davem@davemloft.net> <20130813180036.3e639789@nehalam.linuxnetplumber.net> <520B59D3.4020103@gmail.com> <20130814092022.494caf2b@nehalam.linuxnetplumber.net> <520BCC72.8040002@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org To: poma Return-path: Received: from mail-pb0-f49.google.com ([209.85.160.49]:56992 "EHLO mail-pb0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757806Ab3HOPlZ (ORCPT ); Thu, 15 Aug 2013 11:41:25 -0400 Received: by mail-pb0-f49.google.com with SMTP id xb4so861280pbc.8 for ; Thu, 15 Aug 2013 08:41:25 -0700 (PDT) In-Reply-To: <520BCC72.8040002@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 14 Aug 2013 20:29:06 +0200 poma wrote: > On 14.08.2013 18:20, Stephen Hemminger wrote: > > On Wed, 14 Aug 2013 12:20:03 +0200 > > poma wrote: > > > >> On 14.08.2013 03:00, Stephen Hemminger wrote: > >>> On Tue, 13 Aug 2013 15:09:55 -0700 (PDT) > >>> David Miller wrote: > >>> > >>>> From: Stephen Hemminger > >>>> Date: Sat, 10 Aug 2013 15:02:07 -0700 > >>>> > >>>>> The DMA sync should sync the whole receive buffer, not just > >>>>> part of it. Fixes log messages dma_sync_check. > >>>>> > >>>>> Signed-off-by: Stephen Hemminger > >>>> > >>>> Applied, but I really suspect that your "check DMA mapping errors" > >>>> patch has added a serious regression. A regression much worse than > >>>> the bug you were trying to fix with that change. > >>> > >>> Argh. The problem is deeper than that. Device got broken somewhere between > >>> 3.2 and 3.4. My old Dlink card works on 3.2 but gets DMA errors on 3.4. > >>> The config's are different though so checking that as well. > >>> > >> > >> Can I help you with debugging? > >> DGE-530T is rather solid device. > > > > Don't think it is a hardware problem. > > The failure is when the board access the Receive ring PCI memory area. > > This region is allocated with pci_alloc_consistent and therefore should > > be available. Two possible issues are driver math issues, or hardware > > problems with where the region is located. Some of these cards don't > > really have full 64 bit PCI support. > > > > My board is: > > 05:01.0 Ethernet controller: D-Link System Inc Gigabit Ethernet Adapter (rev 11) > > Subsystem: D-Link System Inc DGE-530T Gigabit Ethernet Adapter > > Flags: bus master, 66MHz, medium devsel, latency 32, IRQ 18 > > Memory at f7d20000 (32-bit, non-prefetchable) [size=16K] > > I/O ports at c000 [size=256] > > Expansion ROM at f7d00000 [disabled] [size=128K] > > Capabilities: [48] Power Management version 2 > > Capabilities: [50] Vital Product Data > > Kernel driver in use: skge > > > > > > What is your config? > > > > 01:09.0 Ethernet controller: D-Link System Inc Gigabit Ethernet Adapter > (rev 11) > Subsystem: D-Link System Inc DGE-530T Gigabit Ethernet Adapter > Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 19 > Memory at fbffc000 (32-bit, non-prefetchable) [size=16K] > I/O ports at b400 [size=256] > [virtual] Expansion ROM at ec000000 [disabled] [size=128K] > Capabilities: [48] Power Management version 2 > Capabilities: [50] Vital Product Data > Kernel driver in use: skge > > > poma > In the course of debugging this, I moved the card to another slot and all the problems went away. I suspect either card insertion or more likely the crap consumer motherboards don't have full PCI support on some slots. There doesn't seem to be anyway to address this in software.