two ata write chaching request

[Xin LI]

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On 12/20/10 15:10, Alexander Best wrote:
> hi there,
> 
> i'd really like to see
> 
> 1) write caching to be turned on and off for individual hdds
>    (i.e. hw.ata.X.wc) and

This is possible.  We may need to split the logic out from ad_init() as
the disk number is not known at that point if I understood the code
correctly.

> 2) to be able to turn write chaching on and off on the fly.

If I understand the code correctly, this is merely issuing a SETFEATURE
at runtime and *should* be possible.  The problem is atacontrol(8) does
not offer a way to issue the command directly as camcontrol(8) do.

> any thoughts on these two topics? is it technically possible?
> 
> cheers.
> alex
> 


- -- 
Xin LI <delphij at delphij.net>	http://www.delphij.net/
FreeBSD - The Power to Serve!	       Live free or die
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