Even if some IOMMU has registered itself on the platform "bus", that doesn't necessarily mean it provides translation for the device we care about. Replace iommu_present() with a more appropriate check.
On Qualcomm platforms the IOMMU can be specified either for the MDP/DPU device or for its parent MDSS device depending on the actual platform. Check both of them, since that is how both DPU and MDP5 drivers work.
Co-developed-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org --- drivers/gpu/drm/msm/msm_drv.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 4a3dda23e3e0..a37a3bbc04d9 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -266,8 +266,14 @@ bool msm_use_mmu(struct drm_device *dev) { struct msm_drm_private *priv = dev->dev_private;
- /* a2xx comes with its own MMU */ - return priv->is_a2xx || iommu_present(&platform_bus_type); + /* + * a2xx comes with its own MMU + * On other platforms IOMMU can be declared specified either for the + * MDP/DPU device or for its parent, MDSS device. + */ + return priv->is_a2xx || + device_iommu_mapped(dev->dev) || + device_iommu_mapped(dev->dev->parent); }
static int msm_init_vram(struct drm_device *dev)