Am 23.05.19 um 11:50 schrieb Christoph Hellwig: > [CAUTION: External Email] > > On Thu, May 23, 2019 at 09:48:40AM +0000, Koenig, Christian wrote: >> I don't adjust the address manually anywhere. I just call >> dma_map_resource() and use the resulting DMA address to access the other >> devices PCI BAR. >> >> At least on my test system (AMD CPU + AMD GPUs) this seems to work >> totally fine. Currently trying to find time and an Intel box to test it >> there as well. > The problem shows up if pci_bus_address() returns a different address > than pci_resource_start(), should be easy to check if that happens. > IIRC it is something mostly seen on embedded SOCs. Ok, we certainly don't have a system which exercise this user case. Could ask around if we have an ARM SOC with that properties somewhere. But asking the other way around: Where is the right place to start fixing all this? dma_map_resource()? Christian.
