On 5/4/2022 5:16 PM, Dmitry Baryshkov wrote:
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@xxxxxxx>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
I have the same question as patch (1) of this series here but i will let
you answer it there, so this one is,
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
---
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)
