On 22 August 2016 at 18:52, Tom Yan [off-list ref] wrote:

For the "payload block size" that is "always" 512-byte as per the same
spec, I don't think we need to concern about it. I think it only
matters if we want to enable multi-block TRIM payload according to the
reported limit in IDENTIFY DEVICE data. Probably it merely means that
the "each of the blocks" in the reported limit will always mean 64
TRIM entries, even on 4Kn drives, instead of 512.

Actually that's what we assumed in our current code that forms the DSM
command as well. See how (hob_)feature for queued TRIM and how
(hob_)nsect for non-queued TRIM are set in ata_scsi_write_same_xlat in
libata-scsi ('size / 512').

So if you are going to increase the payload block size per logical
sector size (in other word, you assume that the payload block size is
_expected_ to be the logical block size, in spite of what ACS told,
you'll need to adjust how the aforementioned fields in the ATA
taskfile are set as well.