The DMA configuration of the virtual device is inherited from the first actual etnaviv device. Unfortunately, this doesn't work with an IOMMU:
[ 5.191008] Failed to set up IOMMU for device (null); retaining platform DMA ops
This is because there is no associated iommu_group with the device. The group is set in iommu_group_add_device() which is eventually called by device_add() via the platform bus: device_add() blocking_notifier_call_chain() iommu_bus_notifier() iommu_probe_device() __iommu_probe_device() iommu_group_get_for_dev() iommu_group_add_device()
Move of_dma_configure() into the probe function, which is called after device_add(). Normally, the platform code will already call it itself if .of_node is set. Unfortunately, this isn't the case here.
Signed-off-by: Michael Walle michael@walle.cc --- drivers/gpu/drm/etnaviv/etnaviv_drv.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c index 2509b3e85709..54eb653ca295 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c @@ -589,6 +589,7 @@ static int compare_str(struct device *dev, void *data) static int etnaviv_pdev_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; + struct device_node *first_node = NULL; struct component_match *match = NULL;
if (!dev->platform_data) { @@ -598,6 +599,9 @@ static int etnaviv_pdev_probe(struct platform_device *pdev) if (!of_device_is_available(core_node)) continue;
+ if (!first_node) + first_node = core_node; + drm_of_component_match_add(&pdev->dev, &match, compare_of, core_node); } @@ -609,6 +613,14 @@ static int etnaviv_pdev_probe(struct platform_device *pdev) component_match_add(dev, &match, compare_str, names[i]); }
+ /* + * Apply the same DMA configuration to the virtual etnaviv + * device as the GPU we found. This assumes that all Vivante + * GPUs in the system share the same DMA constraints. + */ + if (first_node) + of_dma_configure(&pdev->dev, first_node, true); + return component_master_add_with_match(dev, &etnaviv_master_ops, match); }
@@ -662,13 +674,6 @@ static int __init etnaviv_init(void) pdev->dev.coherent_dma_mask = DMA_BIT_MASK(40); pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
- /* - * Apply the same DMA configuration to the virtual etnaviv - * device as the GPU we found. This assumes that all Vivante - * GPUs in the system share the same DMA constraints. - */ - of_dma_configure(&pdev->dev, np, true); - ret = platform_device_add(pdev); if (ret) { platform_device_put(pdev);