Date: Fri, 24 Apr 2009 14:18:40 +0200
From: Joerg Roedel <joerg.roedel@amd.com>
To: David Vrabel <david.vrabel@csr.com>
CC: Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: dma_debug_device_change() gives bogus errors
Message-ID: <20090424121840.GO17438@amd.com>
References: <49F1A064.6040100@csr.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Disposition: inline
In-Reply-To: <49F1A064.6040100@csr.com>
User-Agent: Mutt/1.5.18 (2008-05-17)
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1277
Lines: 30

On Fri, Apr 24, 2009 at 12:20:04PM +0100, David Vrabel wrote:
> dma_debug_device_change() gives bogus errors if a driver unmaps dma
> buffers within its driver->remove() method.  This is because the
> BUS_NOTIFY_UNBIND_DRIVER notification is raised before calling
> driver->remove() (see __device_release_driver() in drivers/base/dd.c).
> 
> By the time my driver->remove() completes, there are no DMA mappings
> (debug_dma_dump_mappings() produces no output).
> 
> Also, somewhat surprisingly, it only prints the error the first time the
> driver is unbound.

Thanks for the report. This is being worked on already. I will disable
this check for 2.6.30 and try to get a solution upstream for 2.6.31.

Joerg

-- 
           | Advanced Micro Devices GmbH
 Operating | Karl-Hammerschmidt-Str. 34, 85609 Dornach bei M?nchen
 System    | 
 Research  | Gesch?ftsf?hrer: Jochen Polster, Thomas M. McCoy, Giuliano Meroni
 Center    | Sitz: Dornach, Gemeinde Aschheim, Landkreis M?nchen
           | Registergericht M?nchen, HRB Nr. 43632

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/