missing disk device under 9-STABLE

[Jeff Blank]

On Sat, Mar 03, 2012 at 09:51:53PM +0200, Alexander Motin wrote:
> This looks like cause of the missing disk:
> 
> ahcich1: Timeout on slot 0 port 0
> ahcich1: is 00000002 cs 00000000 ss 00000000 rs 00000001 tfd 50 serr 
> 00000000 cmd 00006017
> ahcich1: Timeout on slot 0 port 0
> ahcich1: is 00000002 cs 00000000 ss 00000000 rs 00000001 tfd 50 serr 
> 00000000 cmd 00006017
> 
> It tells that controller signals interrupt, but driver haven't got it. 
> That is even more strange after the disk on first SATA port is working 
> fine. You may try to add to your /boot/loader.conf line:
> hint.ahci.0.msi=0
> , or just set it via loader prompt.

Alexander,

Thanks, that seemed to clear the problem up, no troubles through half
a dozen or more reboots.

Is disabling MSI likely to have any side effects on, for example,
performance or reliability?  Is there any point to pursuing this as a
FreeBSD problem, since I didn't have any issues under the old ATA
system?  I'm happy to help troubleshoot this if anyone thinks it's
worth looking into.

thanks,
Jeff