libata: MODE SELECT
Status from this message: applied
Get series with b4
b4 am [email protected]Versions newest first
Patches in v1 Applied
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/2 | libata: MODE SELECT, strengthen mode sensedrivers/ | +102 | 1 reply | |
| 2/2 | libata: MODE SELECT, add commanddrivers/ | +185 | 0 replies |
Reviews trailers per patch
No Reviewed-by, Acked-by or Tested-by trailers for v1 yet.
Cover letter [PATCH 0/2] libata: MODE SELECT
Jeff,
Here is another shot at adding MODE SELECT to libata. I have used sat-r06, sbc-3 and spc-4 as
a guide. Compliance on the ATA side has some issues:
- no mechanism to issue 2 or more ATA commands when translating a single SCSI command [in the upstream branch, there have been patches ...]
- relies on the dev->id array (IDENTIFY DEVICE response) always being up to date. Despite assurances I cannot see how that is the case when multiple hosts (initiators) can access a SATA disk.
This patch is broken into two parts and is against libata-dev's upstream branch:
1) strengthen MODE SENSE processing and make default mode pages visible within libata-scsi.c
2) add MODE SELECT SCSI command support.
Two attributes can be changed with these patches:
- WCE: write cache enable [cache mode page]
- DRA: disable read ahead [cache mode page]
Testing: upstream branch seems to be broken wrt SG_IO as the largest amount of data that can be sent per command is 4 KB. A 50 MB write (segmented to 4 KB per command) slowed down from 14 seconds with WCE=1 to 107 seconds with WCE=0. sg_dd was used for the transfer and sdparm to change WCE. ST380013AS disk and sata_sil LLD.
The attachments are mime text because I wasn't able to do otherwise.
Doug Gilbert