Re: [PATCH v2] drm/msm/mdp5: Find correct node for creating gem address space

From: Bjorn Andersson
Date: Mon Jul 08 2019 - 12:10:32 EST


On Mon 08 Jul 08:12 PDT 2019, Jeffrey Hugo wrote:

> Creating the msm gem address space requires a reference to the dev where
> the iommu is located. The driver currently assumes this is the same as
> the platform device, which breaks when the iommu is outside of the
> platform device (ie in the parent). Default to using the platform device,
> but check to see if that has an iommu reference, and if not, use the parent
> device instead. This should handle all the various iommu designs for
> mdp5 supported systems.
>
> Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@xxxxxxxxx>

Tested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

> ---
>
> v2: It turns out there isn't a universal way to get the iommu device, so
> check to see if its in the current node or parent
>
> drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index 4a60f5fca6b0..02dc7d426cb0 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -663,6 +663,7 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
> struct msm_kms *kms;
> struct msm_gem_address_space *aspace;
> int irq, i, ret;
> + struct device *iommu_dev;
>
> /* priv->kms would have been populated by the MDP5 driver */
> kms = priv->kms;
> @@ -702,7 +703,11 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
> mdelay(16);
>
> if (config->platform.iommu) {
> - aspace = msm_gem_address_space_create(&pdev->dev,
> + iommu_dev = &pdev->dev;
> + if (!iommu_dev->iommu_fwspec)
> + iommu_dev = iommu_dev->parent;
> +
> + aspace = msm_gem_address_space_create(iommu_dev,
> config->platform.iommu, "mdp5");
> if (IS_ERR(aspace)) {
> ret = PTR_ERR(aspace);
> --
> 2.17.1
>