On 5/23/2019 7:43 PM, Christoph Hellwig wrote: > On Thu, May 23, 2019 at 07:35:07AM +0200, Marek Szyprowski wrote: >> Don't we have DMA_BIDIRECTIONAL for such case? > > Not sure if it was intended for that case, but it definitively should > do the right thing for swiotlb, and it should also do the right thing > in terms of cache maintainance. > >> Maybe we should update >> documentation a bit to point that DMA_FROM_DEVICE expects the whole >> buffer to be filled by the device? > > Probably. Horia, can you try to use DMA_BIDIRECTIONAL? > This works, but at the cost of performance - all the cache lines being written back to memory, just to be overwritten by the device.
Thanks, Horia _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
