From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
To: jarkao2@gmail.com
Cc: alan@lxorguk.ukuu.org.uk, davem@davemloft.net,
shemminger@linux-foundation.org, mbreuer@majjas.com,
akpm@linux-foundation.org, flyboy@gmail.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
mchan@broadcom.com, pcnet32@verizon.net, romieu@fr.zoreil.com,
mcarlson@broadcom.com
Subject: Re: [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync
Date: Fri, 22 Jan 2010 00:22:10 +0900 [thread overview]
Message-ID: <20100122002053X.fujita.tomonori@lab.ntt.co.jp> (raw)
In-Reply-To: <20100120225322.GC3072@del.dom.local>
On Wed, 20 Jan 2010 23:53:22 +0100
Jarek Poplawski <jarkao2@gmail.com> wrote:
> On Wed, Jan 20, 2010 at 10:24:14PM +0000, Alan Cox wrote:
> > > > Seems like an underlying bug in the DMA api. Maybe it just can't
> > > > handle operations on partial mapping.
> > > >
> > > > Other drivers with same problem:
> > > > bnx2, cassini, pcnet32, r8169, rrunner, skge, sungem, tg3,
> > >
> > > It seems using the same length (even without pci_unmap_len()) is
> > > crucial here, but I hope maintainers (added to CC) will take care.
> >
> > The API needs fixing - if you've got a large mapping and you want to sync
> > part of it then we need to support that. Now it might well be that the
> > implementation on some braindead platform has to sync the entire thing,
> > and some implementations entire pages or cache lines.
> >
> > You can't fix this in the drivers, they requested a service and they
> > don't have enough information nor is it their job to know about all the
> > platform specific rules.
>
> Yes, the need to repeat some other values if there is a dedicated
> structure/pointer could be misleading. Btw, it seems to be a trivial
> overlooking since there is dma_sync_single_range() ready to use.
Yeah, dma_sync_single_range() enables you to do a partial sync. But
you must be really careful with a partial sync (as DMA-API.txt says).
next prev parent reply other threads:[~2010-01-21 15:23 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-20 9:41 [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync Jarek Poplawski
2010-01-20 18:03 ` Stephen Hemminger
2010-01-20 20:11 ` Michael Chan
2010-01-20 20:30 ` Stephen Hemminger
2010-01-20 20:58 ` Jarek Poplawski
2010-01-20 22:50 ` David Miller
2010-01-20 22:45 ` David Miller
2010-01-20 18:09 ` Stephen Hemminger
2010-01-20 22:24 ` Alan Cox
2010-01-20 22:53 ` David Miller
2010-01-20 22:53 ` Jarek Poplawski
2010-01-21 15:22 ` FUJITA Tomonori [this message]
2010-01-21 18:41 ` Jarek Poplawski
2010-01-22 5:11 ` FUJITA Tomonori
2010-01-22 6:38 ` David Miller
2010-02-03 1:18 ` FUJITA Tomonori
2010-02-03 1:27 ` David Miller
2010-01-21 19:59 ` Michael Breuer
2010-01-21 20:41 ` Jarek Poplawski
2010-01-21 20:46 ` Michael Breuer
2010-01-21 21:02 ` Jarek Poplawski
2010-01-22 18:01 ` Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync) Michael Breuer
2010-01-22 21:53 ` Jarek Poplawski
2010-01-22 22:14 ` Michael Breuer
2010-01-22 23:06 ` Jarek Poplawski
2010-01-22 23:25 ` Michael Breuer
2010-01-22 23:46 ` Jarek Poplawski
2010-01-22 23:50 ` Michael Breuer
2010-01-23 23:21 ` Jarek Poplawski
2010-01-24 1:53 ` Michael Breuer
2010-01-27 15:34 ` Michael Breuer
2010-01-27 16:50 ` Stephen Hemminger
2010-01-27 16:57 ` Michael Breuer
2010-01-27 17:45 ` Stephen Hemminger
2010-01-27 17:57 ` Michael Breuer
2010-01-27 18:33 ` Michael Breuer
2010-01-27 23:54 ` Hang: 2.6.32.4 sky2/DMAR David Miller
2010-01-27 17:56 ` Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: at lib/dma-debug.c:902 check_sync) Stephen Hemminger
2010-01-27 17:58 ` Michael Breuer
2010-01-27 18:08 ` Michael Breuer
2010-01-27 18:45 ` Michael Breuer
2010-01-27 19:23 ` Jarek Poplawski
2010-01-27 19:32 ` Jarek Poplawski
2010-01-28 15:32 ` Michael Breuer
2010-01-28 16:43 ` Michael Breuer
2010-01-28 17:08 ` Stephen Hemminger
2010-01-28 18:46 ` Michael Breuer
2010-01-28 22:34 ` Jarek Poplawski
2010-01-28 22:43 ` Michael Breuer
2010-01-28 22:56 ` Jarek Poplawski
2010-01-28 22:59 ` Michael Breuer
2010-01-28 23:36 ` [PATCH] sky2: receive dma mapping error handling Stephen Hemminger
2010-01-29 0:05 ` Michael Breuer
2010-01-30 16:30 ` Michael Breuer
2010-01-30 16:31 ` Michael Breuer
2010-01-31 0:34 ` Jarek Poplawski
2010-01-31 4:17 ` Michael Breuer
2010-01-31 22:25 ` Jarek Poplawski
2010-01-31 23:58 ` Michael Breuer
2010-01-31 4:55 ` Michael Breuer
2010-01-31 18:50 ` Michael Breuer
2010-01-31 21:58 ` Michael Breuer
2010-01-31 22:18 ` Jarek Poplawski
2010-02-01 0:19 ` Michael Breuer
2010-02-01 4:26 ` Michael Breuer
2010-02-01 10:47 ` Jarek Poplawski
2010-02-01 9:17 ` [PATCH v2] sky2: Fix transmit dma mapping handling Jarek Poplawski
2010-02-01 17:52 ` Michael Breuer
2010-02-01 18:08 ` [PATCH] sky2: receive dma mapping error handling Stephen Hemminger
2010-02-01 18:20 ` Stephen Hemminger
2010-02-01 18:44 ` Michael Breuer
2010-02-01 20:13 ` Jarek Poplawski
2010-02-01 20:41 ` Jarek Poplawski
2010-02-01 21:27 ` [PATCH v3] " Jarek Poplawski
2010-02-01 22:29 ` Stephen Hemminger
2010-02-01 22:46 ` Jarek Poplawski
2010-02-01 22:51 ` Stephen Hemminger
2010-02-01 21:42 ` [PATCH v3b resent] sky2: Fix transmit dma mapping handling Jarek Poplawski
2010-02-03 4:07 ` [PATCH] sky2: receive dma mapping error handling Michael Breuer
2010-02-03 16:47 ` Michael Breuer
2010-02-03 16:56 ` Stephen Hemminger
2010-02-03 17:07 ` Michael Breuer
2010-02-03 18:23 ` Justin P. Mattock
2010-02-03 18:25 ` Stephen Hemminger
2010-02-03 18:48 ` Justin P. Mattock
2010-02-03 17:16 ` Justin P. Mattock
2010-02-02 22:44 ` Andi Kleen
2012-01-16 16:39 ` Regression: sky2 kernel between 3.1 and 3.2.1 (last known good 3.0.9) Michael Breuer
2012-01-20 14:24 ` Michael Breuer
2012-01-20 16:10 ` Stephen Hemminger
2012-01-20 16:17 ` Michael Breuer
2012-01-20 16:26 ` Stephen Hemminger
2012-01-20 16:44 ` Michael Breuer
2012-01-21 15:29 ` Michael Breuer
2012-01-22 18:03 ` Stephen Hemminger
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