Comment 12 for bug 1974100

@Christian - my lsblk output looks very similar to yours. In particular, all device types are reporting discard support; the only difference is the reported discard sizes.

I would suggest that at the end of your tests you check the disk with "debugfs -R dump_unused". I'm seeing disk blocks filled with garbage. I expected them to be filled with zeros.

So, I don't think it's just a feature request. Not only has the device announced discard support, but when you read the blocks back they are not zero filled.