I ran into an issue while working with packed mips for a tiled resource.
Normally, you would update a tile using the UpdateTiles command. However, when a resource mip is less than the dimension of a tile (64 kb), it goes to a special tile together with all other mips that are too small. According to the documentation you should use UpdateSubresource routine to update packed mips.
My problem is that I cannot make this work at all for any mip level greater than 0. UpdateSubresource works on the 0 level well, I can immediately see the change from …