2.0.31-pre9: AIC7xxx stops the show

[Ulrich Windl]

(Even though the kernel died rather cleanly:)

The kernel died while I was making a backup of two complete kernel 
trees from SCSI disk to SCSI tape. It worked for a while, then 
suddenly it stopped.

scsi: aborting due to timeout
Kernel panic: aic7xxx: Waiting List inconsistency; SCB index=255, numscbs=9
In swapper task - not syncing

I have a AHA2940 with a 1GB Conner disk and a HP C1536 DDS drive.
Tagged queueing is enabled with a qsize of 8 for the disk. I also
had enabled SCB paging. (I had this setup for a long time without trouble)

Also there's a bug with the /proc stats that some August-patch from Doug Lefford
removed. I was surprised to see it (With scanning for multiple LUNs enabled
things are even worse):

The aic7xxx driver in 2.0.31-pre9 writes statistic entries for non-existing
IDs and LUNs. I think there was a fix for that already.
Adaptec AIC7xxx driver version: 4.1/3.2
Compile Options:
  AIC7XXX_RESET_DELAY    : 5
  AIC7XXX_TAGGED_QUEUEING: Enabled
  AIC7XXX_PAGE_ENABLE    : Enabled
  AIC7XXX_PROC_STATS     : Enabled

Adapter Configuration:
          SCSI Adapter: Adaptec AHA-294X SCSI host adapter
                        (AIC-787x chipset)
              Host Bus: Single
               Base IO: 0xe000
        Base IO Memory: 0xf9800000
                   IRQ: 11
                  SCBs: Used 4, HW 16, Page 255
            Interrupts: 6381
         Serial EEPROM: True
  Extended Translation: Enabled
        SCSI Bus Reset: Enabled
            Ultra SCSI: Disabled
     Target Disconnect: Enabled

Statistics:
CHAN#A (TGT 0 LUN 0):
nxfers 6362 (6155 read;207 written)
blks(512) rd=83477; blks(512) wr=1056
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     3      5      4   4757    496    246    152    492      0      0
Writes:     0      0      0    160     45      2      0      0      0      0

CHAN#A (TGT 1 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0

CHAN#A (TGT 2 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0

CHAN#A (TGT 3 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0

CHAN#A (TGT 4 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0

CHAN#A (TGT 5 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0

CHAN#A (TGT 6 LUN 0):
nxfers 2 (2 read;0 written)
blks(512) rd=0; blks(512) wr=0
        < 512 512-1K   1-2K   2-4K   4-8K  8-16K 16-32K 32-64K 64-128K >128K
 Reads:     2      0      0      0      0      0      0      0      0      0
Writes:     0      0      0      0      0      0      0      0      0      0


Ulrich Windl