WRITE_SAME is not required to be supported by the command set. The only question here is: Does the device indicate that it supports WRITE_SAME, but then does not? In this case, clear firmware defect that WD would need to fix. Otherwise, clear Linux kernel defect. Don’t issue WRITE_SAME if the device tells you it doesn’t support WRITE_SAME.

But then again most of the people who will comment here are idiots coming from their overlord Fefe, following his retarded narrative without using their own brains for one second.