"ffs_mountroot: can't find rootvp" after cvsup and making worldfmen

[Graham Menhennitt]

Doug White wrote:

>>Anyway, I now have a working kernel. I presume that I should file a PR
>>on this.
>>    
>>
>
>Yes please.
>  
>
Done - kern/79332

>Do you have a long delay at the point where the bogus messages are printed
>in the newer kernel, but in the older? The change implies that it will get
>out of a busted channel faster, but your disk apparently needs a longer
>delay.  If its hanging for the full 30s on the working kernel then that
>woud explain why shortening the dealy ends up with a missing disk.
>  
>
No, there is about a 3 second delay.

>If you want to try another workaround, increase the ata_udelay(100000); by
>2, and progressively longer until your disk reappears. (You may want to
>reduce the for exit condition on timeout since it'll wait 310 iterations.)
>If that doesn't work, start increasing the DELAY()s.
>  
>
I've increased it to 400000 and it fixes the problem - 300000 doesn't. 
I'll update the PR to reflect this.

Thanks for your help,
  Graham