aic7xxx problems, again

[Debian User]

Hello,

I'm having problems with a Adaptec AIC-7892A SCSI adapter 
under kernels >=2.4.19.
It seems to be a common issue, symptoms being error messages

scsi0: PCI error Interrupt at seqaddr = <random address>
scsi0: Data Parity Error Detected during address or write data phase

and (infrequent) _lockups_ during heavy IO. 

I googled around and searched the archives, but didn't find a definite
solution though. It seems the problem could be caused by
CONFIG_AIC7XXX_CMDS_PER_DEVICE=253, but I haven't figured out 
how to determine the right value for it.

The machine is an Athlon with a VIA chipset.

The following kernel options might be relevant:

CONFIG_BLK_DEV_IDESCSI=y
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_SCSI_AIC7XXX=y
#how can I figure out the max command count?
CONFIG_AIC7XXX_CMDS_PER_DEVICE=253
CONFIG_AIC7XXX_RESET_DELAY_MS=15000

Relevant section from /proc/scsi:
Channel A Target 1 Negotiation Settings
        User: 160.000MB/s transfers (80.000MHz DT, offset 255, 16bit)
        Goal: 160.000MB/s transfers (80.000MHz DT, offset 63, 16bit)
        Curr: 160.000MB/s transfers (80.000MHz DT, offset 63, 16bit)
        Channel A Target 1 Lun 0 Settings
                Commands Queued 150694
                Commands Active 0
                Command Openings 64
                Max Tagged Openings 64
                Device Queue Frozen Count 0

# uname -mro
2.4.21 i686 GNU/Linux

# hdparm /dev/hda
/dev/hda:
 multcount    = 16 (on)
 IO_support   =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  1 (on)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 7297/255/63, sectors = 117231408, start = 0

# lspci
00:00.0 Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133] (rev 03)
00:01.0 PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133 AGP]
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev 
40)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586/B/686A/B PIPC Bus 
Master IDE (rev 06)
00:07.4 Bridge: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev 40)
00:0e.0 Ethernet controller: Realtek Semiconductor Co., Ltd. 
RTL-8139/8139C/8139C+ (rev 10)
00:0f.0 SCSI storage controller: Adaptec AIC-7892A U160/m (rev 02)
00:10.0 VGA compatible controller: S3 Inc. 86c325 [ViRGE] (rev 06)

# cat /proc/interrupts
           CPU0
  0:   34240430          XT-PIC  timer
  1:          4          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
 10:    7477682          XT-PIC  eth0
 11:     152077          XT-PIC  aic7xxx
 14:      71461          XT-PIC  ide0
 15:    1864693          XT-PIC  ide1
NMI:          0
LOC:   34225209
ERR:   11631092
MIS:          0

Selected sections from dmesg:
Linux version 2.4.21 (root at blah) (gcc version 3.3 (Debian)) 
Kernel command line: auto BOOT_IMAGE=Linux ro root=801 hdd=ide-scsi
ide_setup: hdd=ide-scsi
Local APIC disabled by BIOS -- reenabling.
Found and enabled local APIC!
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
enabled ExtINT on CPU#0
Using local APIC timer interrupts.
calibrating APIC timer ...
..... CPU clock speed is 996.6128 MHz.
..... host bus clock speed is 199.3225 MHz.
mtrr: v1.40 (20010327) Richard Gooch (rgooch at atnf.csiro.au)
mtrr: detected mtrr type: Intel
PCI: PCI BIOS revision 2.10 entry at 0xfb220, last bus=1
PCI: Using configuration type 1
PCI: Probing PCI hardware
PCI: Using IRQ router VIA [1106/0686] at 00:07.0
Applying VIA southbridge workaround.
PCI: Disabling Via external APIC routing
8139too Fast Ethernet driver 0.9.26
PCI: Found IRQ 10 for device 00:0e.0
eth0: RealTek RTL8139 Fast Ethernet at 0xd0800000, 00:c0:df:04:20:11, IRQ 10
eth0:  Identified 8139 chip type 'RTL-8139B'
Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
VP_IDE: IDE controller at PCI slot 00:07.1
VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci00:07.1
    ide0: BM-DMA at 0xd000-0xd007, BIOS settings: hda:DMA, hdb:pio
    ide1: BM-DMA at 0xd008-0xd00f, BIOS settings: hdc:DMA, hdd:DMA
hda: ST360021A, ATA DISK drive
blk: queue c0303f60, I/O limit 4095Mb (mask 0xffffffff)
hdc: WDC WD1200JB-00DUA3, ATA DISK drive
hdd: PIONEER DVD-RW DVR-104, ATAPI CD/DVD-ROM drive
blk: queue c03043b4, I/O limit 4095Mb (mask 0xffffffff)
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: attached ide-disk driver.
hda: host protected area => 1
hda: 117231408 sectors (60022 MB) w/2048KiB Cache, CHS=7297/255/63, UDMA(100)
hdc: attached ide-disk driver.
hdc: host protected area => 1
hdc: 234441648 sectors (120034 MB) w/8192KiB Cache, CHS=14593/255/63, UDMA(33)
hdd: attached ide-scsi driver.
SCSI subsystem driver Revision: 1.00
PCI: Found IRQ 11 for device 00:0f.0
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.8
        <Adaptec 29160N Ultra160 SCSI adapter>
        aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs

  Vendor: QUANTUM   Model: ATLAS_V__9_WLS    Rev: 0230
  Type:   Direct-Access                      ANSI SCSI revision: 03
(scsi0:A:1): 160.000MB/s transfers (80.000MHz DT, offset 63, 16bit)
scsi0:A:1:0: Tagged Queuing enabled.  Depth 253
scsi1 : SCSI host adapter emulation for IDE ATAPI devices
  Vendor: PIONEER   Model: DVD-RW  DVR-104   Rev: 1.20
  Type:   CD-ROM                             ANSI SCSI revision: 02
Attached scsi disk sda at scsi0, channel 0, id 1, lun 0
SCSI device sda: 17930694 512-byte hdwr sectors (9181 MB)
 sda: sda1 sda2 sda3 sda4 < sda5 sda6 >
Attached scsi CD-ROM sr0 at scsi1, channel 0, id 0, lun 0
sr0: scsi3-mmc drive: 15x/15x writer cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
scsi0: PCI error Interrupt at seqaddr = 0x1a3
scsi0: Data Parity Error Detected during address or write data phase
spurious 8259A interrupt: IRQ7.
eth0: Setting 100mbps half-duplex based on auto-negotiated partner ability 
40a1.
blk: queue c0303f60, I/O limit 4095Mb (mask 0xffffffff)
loop: loaded (max 8 devices)
SCSI cdrom error : host 1 channel 0 id 0 lun 0 return code = 28000000
Current sd0b:00: sense key Blank Check
 I/O error: dev 0b:00, sector 2
(scsi0:A:1:0): Locking max tag count at 64
scsi0: PCI error Interrupt at seqaddr = 0x9
scsi0: Data Parity Error Detected during address or write data phase