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

[Graham Menhennitt]

Doug White wrote:

>On Sat, 26 Mar 2005, Graham Menhennitt wrote:
>
>  
>
>>>>I just cvsupped to the latest RELENG_5 (as of yesterday) and built and
>>>>installed the world and a new kernel. When I boot the new kernel, I get
>>>>an error "ffs_mountroot: can't find rootvp". At the "mountroot>" prompt,
>>>>whatever I type (even '?') causes a crash and reboot. I can still boot
>>>>my old kernel without a problem. The dmesg from the old kernel and a
>>>>capture of the boot of the new kernel are below. Noticably absent from
>>>>the new one is the line "ad0: 76319MB <ST380011A/3.06> [155061/16/63] at
>>>>ata0-master UDMA100" which is my only disk drive.
>>>>        
>>>>
>
>Hm .. from the -v output it looks like the first ATA channel is not
>resetting properly for the probe. We'll need to get a better idea of when
>the problem appears since a lot has changed between January and now.
>  
>
Doug,

I compared the output of "boot -v" for the working and broken kernels. 
It seems that the broken one does fewer loops around the disk probe and 
hence has less lines of
    ata0-master: stat=0x90 err=0x90 lsb=0x90 msb=0x90
than the one that works. Since that line comes from ata-lowlevel.c, I 
cvs'ed versions of that file going back to around when I built the 
working kernel. The following seems to be the change that broke it.

 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
--- ata-lowlevel.c    Mon Mar 28 15:59:57 2005
+++ ata-lowlevel.c_orig    Wed Mar 23 19:17:46 2005
@@ -605,19 +605,26 @@
         }
     }
     if (mask == 0x01)    /* wait for master only */
-        if (!(stat0 & ATA_S_BUSY) || (stat0 == 0xff && timeout > 5))
+        if (!(stat0 & ATA_S_BUSY) || (stat0 == 0xff && timeout > 5) ||
+        (stat0 == err && lsb == err && msb == err && timeout > 5))
         break;
     if (mask == 0x02)    /* wait for slave only */
-        if (!(stat1 & ATA_S_BUSY) || (stat1 == 0xff && timeout > 5))
+        if (!(stat1 & ATA_S_BUSY) || (stat1 == 0xff && timeout > 5) ||
+        (stat1 == err && lsb == err && msb == err && timeout > 5))
         break;
     if (mask == 0x03) {    /* wait for both master & slave */
         if (!(stat0 & ATA_S_BUSY) && !(stat1 & ATA_S_BUSY))
         break;
-        if (stat0 == 0xff && timeout > 5)
+        if ((stat0 == 0xff && timeout > 5) ||
+        (stat0 == err && lsb == err && msb == err && timeout > 5))
         mask &= ~0x01;
-        if (stat1 == 0xff && timeout > 5)
+        if ((stat1 == 0xff && timeout > 5) ||
+        (stat1 == err && lsb == err && msb == err && timeout > 5))
         mask &= ~0x02;
     }
+    if (mask == 0 && !(stat0 & ATA_S_BUSY) && !(stat1 & ATA_S_BUSY))
+        break;
+
     ata_udelay(100000);
     }   
 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Anyway, I now have a working kernel. I presume that I should file a PR 
on this.

Thanks again for your help.
    Graham