Tejun Heo wrote:

quoted

Aside from the issue above, as I mentioned elsewhere, lots of NCQ drives
don't support non-NCQ FUA writes..

To me, using the NCQ FUA bit on such drives doesn't seem to be a good
idea.  Maybe I'm just too chicken but it's not like we can gain a lot
from doing FUA at this point.  Are there a lot of drives which support
NCQ but not FUA opcodes?

Well, it's hard to say whether "lots" have this issue, but the ones I 
have in my machine, Seagate 7200.7 NCQ 160GB (ST3160827AS) and 7200.10 
320GB (ST3320620AS), both support NCQ and don't support non-NCQ FUA, and 
those (especially the latter) seem to be very popular models.

Likely Seagate didn't implement that command since they figured nobody 
would use that if they had NCQ..

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Robert Hancock      Saskatoon, SK, Canada
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