On Wednesday, September 7, 2016 2:33:13 PM CEST Peter Chen wrote: > > > > Right, that should make it work with iommu as well. However, it does > > not solve the other issue I mentioned above, with boards that have > > USB devices hardwired to a chipidea host controller that need > > configuration from DT. For that, we still need to come up with another > > way to associate the DT hierarchy in the host bridge node with > > the Linux platform_device. > > > > Why? The DMA configuration is for host controller, not for USB device. > No matter there is hardwired or hotplug devices, the DMA configuration > for host controller are both inherited from glue layer platform devices, > current implementation is at function ci_hdrc_add_device, > drivers/usb/chipidea/core.c.
I wasn't referring to DMA configuration there, but only to how we set the of_node pointer in register_root_hub, which you added in dc5878abf49 ("usb: core: move root hub's device node assignment after it is added to bus") as: usb_dev->dev.of_node = parent_dev->of_node; As I understand, parent_dev (aka hcd->self.controller) here refers to the device that you add in ci_hdrc_add_device(), which does not have an of_node pointer, so we actually want parent_dev->parent->of_node. I'm sure you understand that code better than me, so let me know what my mistake is if this indeed works correctly. Regarding the DMA configuration that you mention in ci_hdrc_add_device(), I think we should replace pdev->dev.dma_mask = dev->dma_mask; pdev->dev.dma_parms = dev->dma_parms; dma_set_coherent_mask(&pdev->dev, dev->coherent_dma_mask); with of_dma_configure(), which has the chance to configure more than just those three, as the dma API might look into different aspects: - iommu specific configuration - cache coherency information - bus type - dma offset - dma_map_ops pointer We try to handle everything in of_dma_configure() at configuration time, and that would be the place to add anything else that we might need in the future. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html