Promise SATA 300 TX4

[Nathan Butcher]

>I tried to roll back to right before the above mentioned change
>Karsten (well, I assume it was him  :-)  ) noted on IRC that it might
>be the cause of the problems since I have a similar controller, though
>not exactly the same one, but it didn't fix the timeouts for me.

>For this server I have 3 disks in a graid3 (so no ZFS but the errors
>are similar to what I have seen / heard about wrt. ZFS + ata use) and
>I get timeouts several times a day which causes FreeBSD to loose
>contact with one or more disks where I have to reboot before things
>recover (usually FreeBSD panic's enough so the system reboots by
>itself).

I'm certain that the issue with this card isn't limited to ZFS. It's
been seen before in the 6.x series too.

I really would like to find out which code changes ruined the card's
correct operation... if that could help the ata maintainer in some way.
Unfortunately my csup-fu isn't that strong, otherwise I would send my
source tree back to June 15th and analyse daily buildworlds from that
date until I could pin-point the exact date and file changes that caused
the problem all of us are seeing.

Could someone teach me how to do csup rollbacks to a specific date in
the source tree? If it's not obvious already, I'd really like to squash
this bug.