RFC: ATA to CAM integration patch (and gjournaled
mav at FreeBSD.org
Tue Jul 7 19:06:28 UTC 2009
Harald Schmalzbauer wrote:
> One thing I'm missing is the possibility to spin down the drive.
> I have my system on a SSD, the HD is just for ports nad stuff which
> usually I don't make use of.
> Is that planned to be integrated?
There is no problem, it just wasn't done yet. It should be possible to
submit respective ATA command via CAM pass interface to spin-down drive
immediately or to set wanted power management level, but respective
user-level part in camcontrol is also not implemented yet.
> Another question is why "camcontrol tur ada0" returns "Unit is not ready"
> readcap also doesn't work.
It is all SCSI commands. This implementation expects real direct ATA
operation without SCSI emulation parts. But this commands should work
for ATAPI devices, that are really SCSI deep inside.
> My SSD reports write and read cache present, but disabled. Is the report
> or the status bad?
> Feature Support Enable Value Vendor
> write cache yes no
> read ahead yes no
It is probably the truth. Existing ATA driver enables this features
during drive reset sequence. New one doesn't do it yet.
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