Any objections/comments on axing out old ATA stack?

[Matthew Jacob]

On 3/27/2013 2:22 PM, Alexander Motin wrote:
> Hi.
>
> Since FreeBSD 9.0 we are successfully running on the new CAM-based ATA 
> stack, using only some controller drivers of old ata(4) by having 
> `options ATA_CAM` enabled in all kernels by default. I have a wish to 
> drop non-ATA_CAM ata(4) code, unused since that time from the head 
> branch to allow further ATA code cleanup.
>
> Does any one here still uses legacy ATA stack (kernel explicitly built 
> without `options ATA_CAM`) for some reason, for example as workaround 
> for some regression? Does anybody have good ideas why we should not 
> drop it now?
>
Some people have expressed performance concerns about ATA_CAM. I have 
not validated those concerns. Does anyone know of any?