On Mon, Jan 21, 2019 at 12:28:30AM -0800, h...@infradead.org wrote: > On Mon, Jan 21, 2019 at 04:51:57AM +0000, Peng Fan wrote: > > on i.MX8QM, M4_1 is communicating with DomU using rpmsg with a fixed > > address as the dma mem buffer which is predefined. > > > > Without this patch, the flow is: > > vring_map_one_sg -> vring_use_dma_api > > -> dma_map_page > > -> __swiotlb_map_page > > ->swiotlb_map_page > > ->__dma_map_area(phys_to_virt(dma_to_phys(dev, > > dev_addr)), size, dir); > > However we are using per device dma area for rpmsg, phys_to_virt > > could not return a correct virtual address for virtual address in > > vmalloc area. Then kernel panic. > > And that is the right thing to do. You must not call dma_map_* on > memory that was allocated from dma_alloc_*. > > We actually have another thread which appears to be for this same issue.
Sorry, which thread do you refer to? -- MST
