Re: [PATCH v3 0/2] ata: DSM TRIM fix and improvements

On 7/2/26 7:59 PM, Niklas Cassel wrote:
> Hello all,
> 
> This fixes DSM TRIM for 4Kn devices, which has ironically been broken
> since commit ef2d7392c4ec ("libata: SCT Write Same / DSM Trim"), which
> claimed to correct the DSM TRIM handling for 4Kn devices.
> 
> 
> The first commit is a small fix that can be backported, which limits
> the DSM TRIM to what we currently report in the Block Limits VPD page.
> We currently report a single 512 byte page of entries, i.e. 64 Entries,
> where each entry has a maximum of U16_MAX logical blocks.
> 
> The second commit:
> -Improves the support by reading the MAX PAGES PER DSM COMMAND limit and
>  populates the Block Limits VPD page accordingly.
> -Modifies ata_scsi_write_same_xlat() to properly support up to this amount
>  of pages.
> -Removed the intermediate copying to ata_scsi_rbuf, writes to the scsi
>  buffer directly.
> 
> Practically, sd still caps n_block at SD_MAX_WS16_BLOCKS
> (~3 pages actually used on 4Kn), so while removing the limit on
> ATA_SCSI_RBUF_SIZE (2048) - i.e. 4 pages), we will still be limited
> by SD_MAX_WS16_BLOCKS. The main improvement is not longer taking the
> ata_scsi_rbuf_lock and doing and extra copy from ata_scsi_rbuf.

Applied to for-7.3. Thanks!

-- 
Damien Le Moal
Western Digital Research