stable sata patch: panic at kernel boot (can't dump)

[Doug Ambrisko]

Dmitry Morozovsky writes:
| Dear Doug,
| 
| trying to boot RELENG_4 kernel with your patches (sata_7) on our FTP I got 
| kernel panic (page fault in kernel mode, pid 2, no dump possible). Hardware 
| involved:
| 
| root at kucha:~# grep ata /var/run/dmesg.boot 
| atapci0: <Promise ATA66 controller> port 0xa000-0xa03f,0x9c00-0x9c03,0x9800-0x9807,0x9400-0x9403,0x9000-0x9007 mem 0xed100000-0xed11ffff irq 11 at device 8.0 on pci0
| ata2: at 0x9000 on atapci0
| ata3: at 0x9800 on atapci0
| atapci1: <CMD 649 ATA100 controller> port 0xb400-0xb40f,0xb000-0xb003,0xac00-0xac07,0xa800-0xa803,0xa400-0xa407 irq 10 at device 9.0 on pci0
| ata4: at 0xa400 on atapci1
| ata5: at 0xac00 on atapci1
| atapci2: <VIA 8233 ATA133 controller> port 0xbc00-0xbc0f at device 17.1 on pci0
| ata0: at 0x1f0 irq 14 on atapci2
| ata1: at 0x170 irq 15 on atapci2
| ad0: 238475MB <WDC WD2500JB-00EVA0> [484521/16/63] at ata0-master UDMA100
| ad2: 114473MB <WDC WD1200JB-00CRA1> [232581/16/63] at ata1-master UDMA100
| ad4: 76319MB <WDC WD800JB-00CRA1> [155061/16/63] at ata2-master UDMA66
| ad6: 76319MB <WDC WD800BB-00CJA1> [155061/16/63] at ata3-master UDMA66
| ad8: 57241MB <WDC WD600BB-00CCB0> [116301/16/63] at ata4-master UDMA100
| 
| Kernel paniced just after sio0/sio1, where basic RELENG_4 starts ata channel 
| probes. No serial console at the moment, alas.
| 
| Unfortunately I can't bring this machine out of service for long time; however, 
| we can survive occasional reboots/crashes. What other info can I provide to 
| debug this?

I'd like some clarification.  Does the system boot sometimes and other times
is doesn't?  Once the system is up does it stay up for a while?  It doesn't 
seem like you are not using RAID.  I have a couple more ata bug fixes that
I need to roll into another patchset.  It fixes a bug in which DMA transfers
have not been cancelled when the controller is reset.  I fixed another
panic situation in version 8 that happens on boot if you have a bad sector
at the beginning of the drive.  I'd wait to version 9.  I should be able
to get that out later today.

Another thing that you might want to do is monitor dmesgs for any 
ata/ad errors while the system is running.  Most panics happen later 
after the first error message.  Also you could try looking at 
/var/log/messages.

Thanks,

Doug A.