# Re: \[RFC\] libata-scsi: make sure Maximum Write Same Length is not too large

- From: Martin K. Petersen \<hidden\>
- Date: 2016-08-16 04:15:15 
- List: linux-ide
- Page: https://ratatoskr.run/linux-ide/2016/08/6369151
- Thread: https://ratatoskr.run/linux-ide/2016/08/6369151/t.md

```text
>>>>> "Tom" == Tom Yan [ref] writes:

Tom,

Tom> The thing is, as of ACS-4, blocks that carry DSM/TRIM LBA Range
Tom> Entries are always 512-byte.

Lovely. And SAT conveniently ignores this entirely.

Tom> Honestly, I have no idea how that would work on a 4Kn SSD, if it is
Tom> / will ever be a thing.

Highly unlikely.

But I guess you would have to report 8 512-byte ranges in the 4Kn
case. And then rely on the patch we talked about to clamp the number of
sectors based on the block layer limit.

-- 
Martin K. Petersen	Oracle Linux Engineering
```