On Thu, Nov 29, 2018 at 10:54 AM Christoph Hellwig <hch@xxxxxx> wrote: > > On Thu, Nov 29, 2018 at 09:42:50AM -0500, Rob Clark wrote: > > Maybe the thing we need to do is just implement a blacklist of > > compatible strings for devices which should skip the automatic > > iommu/dma hookup. Maybe a bit ugly, but it would also solve a problem > > preventing us from enabling per-process pagetables for a5xx (where we > > need to control the domain/context-bank that is allocated by the dma > > api). > > You can detach from the dma map attachment using arm_iommu_detach_device, > which a few drm drivers do, but I don't think this is the problem. I think even with detach, we wouldn't end up with the context-bank that the gpu firmware was hard-coded to expect, and so it would overwrite the incorrect page table address register. (I could be mis-remembering that, Jordan spent more time looking at that. But it was something along those lines.) BR, -R _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
