From: "David S. Miller" <davem@redhat.com>
To: Andi Kleen <ak@muc.de>
Cc: gibbs@scsiguy.com, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org
Subject: Re: [BUG] x86_64 pci_map_sg modifies sg list - fails multiple map/unmaps
Date: Mon, 5 Jan 2004 12:35:09 -0800 [thread overview]
Message-ID: <20040105123509.4bacf670.davem@redhat.com> (raw)
In-Reply-To: <m3brpi41q0.fsf@averell.firstfloor.org>
On Mon, 05 Jan 2004 20:47:19 +0100
Andi Kleen <ak@muc.de> wrote:
> Actually I disabled merging by default in the latest x86-64 code,
> but it can be still enabled by the user using options (it makes some
> adapters run several percent faster). I would appreciate if you could
> fix the problem anyways.
>
> I was actually planning to add a BUG() for this. Should do that.
> There is already one that triggers often when the problem occurs.
Andi, you must not modify sg->length in any way shape or form.
The following is legal:
pci_map_sg(..&sg);
pci_unmap_sg(...&sg);
pci_map_sg(..&sg);
If you must modify the length field for DMA, you must have a seperate
dma_length member of the scatterlist structure on your platform, see what
sparc64 does here.
If the documentation states this wrongly, it's a doc bug.
next prev parent reply other threads:[~2004-01-05 20:41 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-05 17:57 [BUG] x86_64 pci_map_sg modifies sg list - fails multiple map/unmaps Justin T. Gibbs
2004-01-05 19:22 ` David S. Miller
2004-01-05 19:41 ` Badari Pulavarty
2004-01-05 19:47 ` Andi Kleen
2004-01-05 20:04 ` Justin T. Gibbs
2004-01-05 20:35 ` David S. Miller [this message]
2004-01-05 21:10 ` Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2004-01-05 19:29 Berkley Shands
2004-01-05 19:28 ` David S. Miller
2004-01-05 20:00 Berkley Shands
[not found] <2938942704.1073325455@aslan.btc.adaptec.com.suse.lists.linux.kernel>
[not found] ` <m3brpi41q0.fsf@averell.firstfloor.org.suse.lists.linux.kernel>
[not found] ` <2997092704.1073333041@aslan.btc.adaptec.com.suse.lists.linux.kernel>
2004-01-05 20:58 ` Andi Kleen
[not found] <200401051929.i05JTsM0000014248@mudpuddle.cs.wustl.edu.suse.lists.linux.kernel>
[not found] ` <20040105112800.7a9f240b.davem@redhat.com.suse.lists.linux.kernel>
2004-01-05 21:02 ` Andi Kleen
2004-01-05 21:01 ` David S. Miller
2004-01-05 21:31 ` Andi Kleen
2004-01-06 0:05 ` James Bottomley
2004-01-06 3:06 ` Andi Kleen
2004-01-06 3:04 ` David S. Miller
2004-01-06 3:14 ` James Bottomley
2004-01-07 15:35 Berkley Shands
2004-01-07 19:19 ` badari
2004-01-07 16:33 Berkley Shands
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