I read over the thread about the VIA chipset problems on the A7V
motherboard, but I hadn't actually seen anything myself until
tonight, when I went to a 1.5.1_BETA kernel from a 1.5 kernel.

Suddenly, the drive will only operate in PIO mode 4:

pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to Ultra-DMA mode 2
wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
wd0d: aborted command, interface CRC error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to Ultra-DMA mode 1
wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA data transfers)
wd0d: DMA error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to PIO mode 4
wd0(pciide1:0:0): using PIO mode 4
wd0d: aborted command, interface CRC error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
wd0: soft error (corrected)


... after rereading the thread, I turned off PCI Delay Transaction
and PCI Master Read Caching in the BIOS, but the problem persists.  If
I drop back to the 1.5 kernel, things work OK.

I'm perfectly willing (not happy, but willing) to accept that this is
crappy hardware, but why was the problem not manifesting itself
under 1.5?


Here's the complete dmesg output, and thanks in advance for any
enlightenment tossed my way:

NetBSD 1.5.1_BETA (DESKTOP) #3: Thu Apr 19 21:06:17 PDT 2001
    riz@desktop.boogers.sf.ca.us:/usr/src/sys/arch/i386/compile/DESKTOP
cpu0: AMD K7 (Athlon) (686-class), 1009.04 MHz
total memory = 255 MB
avail memory = 233 MB
using 3296 buffers containing 13184 KB of memory
BIOS32 rev. 0 found at 0xf0f50
PCI BIOS rev. 2.1 found at 0xf1150
pcibios: config mechanism [1][x], special cycles [1][x], last bus 1
PCI IRQ Routing Table rev. 1.0 found at 0xf1720, size 176 bytes (9 entries)
PCI Interrupt Router at 000:04:0 (vendor 0x1106 product 0x0686)
mainbus0 (root)
pnpbios0 at mainbus0: code f0000, data f0000, entry c2e0, control 0 eventp 0
pnpbios0: nodes 16, max len 114
pnpbios0: node index mismatch (static): requested 0, got 1
PNP0401 (io 378-37f 778-77f, irq 7, dma 3) at pnpbios0 index 0 ignored
PNP0501 (io 3f8-3ff, irq 4) at pnpbios0 index 2 ignored
PNP0501 (io 2f8-2ff, irq 3) at pnpbios0 index 3 ignored
PNP0700 (io 3f2-3f5, irq 6, dma 2) at pnpbios0 index 4 ignored
PNPB02F (io 200-207) at pnpbios0 index 5 ignored
PNP0F13 (irq 12) at pnpbios0 index 8 ignored
PNP0C01 (mem 0-9ffff 100000-fffffff e8000-effff f0000-f3fff f4000-f7fff f8000-fffff ce000-cffff fffe0000-ffffffff) at pnpbios0 index 9 ignored
PNP0000 (io 20-21 a0-a1 4d0-4d1, irq 2) at pnpbios0 index 10 ignored
PNP0100 (io 40-43, irq 0) at pnpbios0 index 11 ignored
PNP0B00 (io 70-75, irq 8) at pnpbios0 index 12 ignored
PNP0303 (io 60 64, irq 1) at pnpbios0 index 13 ignored
PNP0C04 (io f0, irq 13) at pnpbios0 index 14 ignored
PNP0200 (io 0-f 80-90 94-9f c0-de, dma 4) at pnpbios0 index 15 ignored
PNP0800 (io 61) at pnpbios0 index 16 ignored
PNP0A03 (io cf8-cff) at pnpbios0 index 17 ignored
PNP0C02 (io e400-e47f e800-e83f) at pnpbios0 index 18 ignored
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled
pchb0 at pci0 dev 0 function 0
pchb0: vendor 0x1106 product 0x0305 (rev. 0x02)
ppb0 at pci0 dev 1 function 0: vendor 0x1106 product 0x8305 (rev. 0x00)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
vga0 at pci1 dev 0 function 0: vendor 0x10de product 0x002d (rev. 0x15)
wsdisplay0 at vga0: console (80x25, vt100 emulation)
pcib0 at pci0 dev 4 function 0
pcib0: vendor 0x1106 product 0x0686 (rev. 0x22)
pciide0 at pci0 dev 4 function 1: VIA Tech VT82C586A IDE Controller (rev. 0x10)
pciide0: bus-master DMA support present
pciide0: Ultra/66 capable
pciide0: primary channel configured to compatibility mode
atapibus0 at pciide0 channel 0
cd0 at atapibus0 drive 0: <Hewlett-Packard CD-Writer Plus 9100, YMPAR3F8AV, 1.0c> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: primary channel interrupting at irq 14
cd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
pciide0: secondary channel configured to compatibility mode
atapibus1 at pciide0 channel 1
cd1 at atapibus1 drive 0: <TOSHIBA DVD-ROM SD-M1402, 4000109584, 1008> type 5 cdrom removable
cd1: 32-bit data port
cd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: secondary channel interrupting at irq 15
cd1(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
uhci0 at pci0 dev 4 function 2: vendor 0x1106 product 0x3038 (rev. 0x10)
uhci0: interrupting at irq 9
usb0 at uhci0: USB revision 1.0
uhub0 at usb0
uhub0: vendor 0x1106 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1 at pci0 dev 4 function 3: vendor 0x1106 product 0x3038 (rev. 0x10)
uhci1: interrupting at irq 9
usb1 at uhci1: USB revision 1.0
uhub1 at usb1
uhub1: vendor 0x1106 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
pchb1 at pci0 dev 4 function 4
pchb1: vendor 0x1106 product 0x3057 (rev. 0x30)
eap0 at pci0 dev 10 function 0: vendor 0x1274 product 0x1371 CT5880C (rev. 0x02)
eap0: interrupting at irq 5
eap0: Asahi Kasei AK4540 codec; no 3D stereo
audio0 at eap0: full duplex, mmap, independent
midi0 at eap0: AudioPCI MIDI UART
tlp0 at pci0 dev 12 function 0: DECchip 21140A Ethernet, pass 2.2
tlp0: interrupting at irq 11
tlp0: Ethernet address 00:80:c8:27:0e:17
lxtphy0 at tlp0 phy 0: LXT970 10/100 media interface, rev. 1
lxtphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
pciide1 at pci0 dev 17 function 0: Promise Ultra100/ATA Bus Master IDE Accelerator (rev. 0x02)
pciide1: bus-master DMA support present
pciide1: primary channel configured to native-PCI mode
pciide1: using irq 10 for native-PCI interrupt
wd0 at pciide1 channel 0 drive 0: <WDC WD307AA>
wd0: drive supports 16-sector pio transfers, lba addressing
wd0: 29333 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 60074784 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 4
wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 4 (using DMA data transfers)
pciide1: secondary channel configured to native-PCI mode
pciide1: disabling secondary channel (no drives)
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pmsi0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
wsmouse0 at pmsi0 mux 0
lpt0 at isa0 port 0x378-0x37b irq 7
pcppi0 at isa0 port 0x61
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
isapnp0: no ISA Plug 'n Play devices found
apm0 at mainbus0: Power Management spec V1.2
biomask e745 netmask ef45 ttymask ffc7
uhub2 at uhub1 port 2
uhub2: ALCOR Generic USB Hub, class 9/0, rev 1.10/1.00, addr 2
uhub2: 4 ports with 4 removable, self powered
pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to Ultra-DMA mode 2
wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
wd0d: aborted command, interface CRC error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to Ultra-DMA mode 1
wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA data transfers)
wd0d: DMA error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
pciide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
pciide1:0:0: bus-master DMA error: missing interrupt, status=0x21
wd0: transfer error, downgrading to PIO mode 4
wd0(pciide1:0:0): using PIO mode 4
wd0d: aborted command, interface CRC error reading fsbn 0 (wd0 bn 0; cn 0 tn 0 sn 0), retrying
wd0: soft error (corrected)
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs
wsdisplay0: screen 1 added (80x25, vt100 emulation)
wsdisplay0: screen 2 added (80x25, vt100 emulation)
wsdisplay0: screen 3 added (80x25, vt100 emulation)
wsdisplay0: screen 4 added (80x25, vt100 emulation)
wsmux1: connecting to wsdisplay0



+j

-- 
Jeff Rizzo                                         http://boogers.sf.ca.us/~riz