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References: <20190410215327.8024-1-swood@redhat.com> <20190411123314.GA19198@hao-dev>
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From:   Moritz Fischer <moritz.fischer.private@gmail.com>
Date:   Thu, 11 Apr 2019 09:35:52 -0700
Message-ID: <CAJYdmeNX9F_EmTPBjQ1SXOOU=JBA1kBO6WEjBXTmJux4O-CR5A@mail.gmail.com>
Subject: Re: [PATCH] fpga: dfl: afu: Pass the correct device to dma_mapping_error()
To:     Wu Hao <hao.wu@intel.com>
Cc:     Scott Wood <swood@redhat.com>, Alan Tull <atull@kernel.org>,
        linux-fpga@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Scott,

good catch!

On Thu, Apr 11, 2019 at 5:49 AM Wu Hao <hao.wu@intel.com> wrote:
>
> On Wed, Apr 10, 2019 at 04:53:27PM -0500, Scott Wood wrote:
> > dma_mapping_error() was being called on a different device struct than
> > what was passed to map/unmap.  Besides rendering the error checking
> > ineffective, it caused a debug splat with CONFIG_DMA_API_DEBUG.
> >
> > Signed-off-by: Scott Wood <swood@redhat.com>
>
> Hi Scott,
>
> Looks good to me. Thanks for catching this issue.
>
> Acked-by: Wu Hao <hao.wu@intel.com>
>
> Hao
>
> > ---
> >  drivers/fpga/dfl-afu-dma-region.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-region.c
> > index e18a786fc943..cd68002ac097 100644
> > --- a/drivers/fpga/dfl-afu-dma-region.c
> > +++ b/drivers/fpga/dfl-afu-dma-region.c
> > @@ -399,7 +399,7 @@ int afu_dma_map_region(struct dfl_feature_platform_data *pdata,
> >                                   region->pages[0], 0,
> >                                   region->length,
> >                                   DMA_BIDIRECTIONAL);
> > -     if (dma_mapping_error(&pdata->dev->dev, region->iova)) {
> > +     if (dma_mapping_error(dfl_fpga_pdata_to_parent(pdata), region->iova)) {
> >               dev_err(&pdata->dev->dev, "failed to map for dma\n");
> >               ret = -EFAULT;
> >               goto unpin_pages;
> > --
> > 1.8.3.1

Acked-by: Moritz Fischer <mdf@kernel.org>

Thanks
Moritz