Aw: Re: [BUG] "access dev->iommu_fwspec" cause crash on BPI-R2

[Frank Wunderlich]

Hi,

thanks for quick reply, this seems to fix it

no crash, xserver works, like revert of the commit...pushed the fix to below github-repo

regards Frank


> Gesendet: Dienstag, 22. Januar 2019 um 17:49 Uhr
> Von: "Joerg Roedel" <joro@xxxxxxxxxx>
> An: "Frank Wunderlich" <frank-w@xxxxxxxxxxxxxxx>
> Cc: "Matthias Brugger" <matthias.bgg@xxxxxxxxx>, iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx, linux-mediatek@xxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, "Ryder Lee" <ryder.lee@xxxxxxxxxxxx>
> Betreff: Re: [BUG] "access dev->iommu_fwspec" cause crash on BPI-R2
>
> Hi Frank,
> 
> thanks for the report!
> 
> On Tue, Jan 22, 2019 at 05:09:09PM +0100, Frank Wunderlich wrote:
> > Hi,
> > 
> > the following Patch breaks hdmi (at least) on Bananapi R2 (mt7623):
> > 
> > a9bf2eec5a6fc01a0a5250eaf0bf61dfd382a78a "iommu/mediatek: Use helper functions to access dev->iommu_fwspec"
> 
> Does the attached diff fix the issue for you?
> 
> Thanks,
> 
> 	Joerg
> 
> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
> index 6ede4286b835..f60bdb85c4c0 100644
> --- a/drivers/iommu/mtk_iommu_v1.c
> +++ b/drivers/iommu/mtk_iommu_v1.c
> @@ -442,6 +442,10 @@ static int mtk_iommu_add_device(struct device *dev)
>  		iommu_spec.args_count = count;
>  
>  		mtk_iommu_create_mapping(dev, &iommu_spec);
> +
> +		/* dev->iommu_fwspec might have changed */
> +		fwspec = dev_iommu_fwspec_get(dev);
> +
>  		of_node_put(iommu_spec.np);
>  	}
>  
>