Re: [PATCH] drm/msm/adreno: fix probe without iommu

[Jordan Crouse]

On Fri, Sep 11, 2020 at 06:08:53PM +0200, Luca Weiss wrote:
> The function iommu_domain_alloc returns NULL on platforms without IOMMU
> such as msm8974. This resulted in PTR_ERR(-ENODEV) being assigned to
> gpu->aspace so the correct code path wasn't taken.
> 
> Fixes: ccac7ce373c1 ("drm/msm: Refactor address space initialization")
> Signed-off-by: Luca Weiss <luca@xxxxxxxxx>

Reviewed-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 862dd35b27d3..6e8bef1a9ea2 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -189,10 +189,16 @@ struct msm_gem_address_space *
>  adreno_iommu_create_address_space(struct msm_gpu *gpu,
>  		struct platform_device *pdev)
>  {
> -	struct iommu_domain *iommu = iommu_domain_alloc(&platform_bus_type);
> -	struct msm_mmu *mmu = msm_iommu_new(&pdev->dev, iommu);
> +	struct iommu_domain *iommu;
> +	struct msm_mmu *mmu;
>  	struct msm_gem_address_space *aspace;
>  
> +	iommu = iommu_domain_alloc(&platform_bus_type);
> +	if (!iommu)
> +		return NULL;
> +
> +	mmu = msm_iommu_new(&pdev->dev, iommu);
> +
>  	aspace = msm_gem_address_space_create(mmu, "gpu", SZ_16M,
>  		0xffffffff - SZ_16M);
>  
> -- 
> 2.28.0
> 

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