From mboxrd@z Thu Jan  1 00:00:00 1970
From: laurent.pinchart@ideasonboard.com (Laurent Pinchart)
Date: Tue, 13 Jan 2015 17:42:25 +0200
Subject: [PATCH 2/2] ARM: dma-mapping: don't detach devices without an
 IOMMU during teardown
In-Reply-To: <20150113152445.GD31784@arm.com>
References: <1421083413-24798-1-git-send-email-will.deacon@arm.com>
 <2890986.UZklX6cuTS@avalon> <20150113152445.GD31784@arm.com>
Message-ID: <3121960.76S1loDMb2@avalon>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Will,

On Tuesday 13 January 2015 15:24:45 Will Deacon wrote:
> On Tue, Jan 13, 2015 at 02:53:44PM +0000, Laurent Pinchart wrote:
> > On Monday 12 January 2015 17:23:33 Will Deacon wrote:
> > > When tearing down the DMA ops for a device via of_dma_deconfigure, we
> > > unconditionally detach the device from its IOMMU domain. For devices
> > > that aren't actually behind an IOMMU, this produces a "Not attached"
> > > warning message on the console.
> > > 
> > > This patch changes the teardown code so that we don't detach from the
> > > IOMMU domain when there isn't an IOMMU dma mapping to start with.
> > > 
> > > Repoerted-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > I might have reported the problem, but I haven't repoerted it :-)
> 
> D'oh, fat fingers. Sorry!
> 
> > > Signed-off-by: Will Deacon <will.deacon@arm.com>
> > > ---
> > > 
> > >  arch/arm/mm/dma-mapping.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> > > index 7864797609b3..711c3d2802fb 100644
> > > --- a/arch/arm/mm/dma-mapping.c
> > > +++ b/arch/arm/mm/dma-mapping.c
> > > @@ -2023,7 +2023,10 @@ static bool arm_setup_iommu_dma_ops(struct device
> > > *dev, u64 dma_base, u64 size,
> > > 
> > >  static void arm_teardown_iommu_dma_ops(struct device *dev)
> > >  {
> > > 
> > > -	struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> > > +	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> > 
> > As the function is already protected by an #ifdef CONFIG_ARM_DMA_USE_IOMMU
> > is there a specific reason for this change ?
> 
> I just wanted to hide the archdata access, since we shouldn't really care
> where it's stored. I could do it as a seperate patch, but I was in the
> area...

No issue about that, but you could then send another patch to replace all 
direct references to dev->archdata.mapping in the file.

-- 
Regards,

Laurent Pinchart