SCSI warning

[David Xu <davidxu@xxxxxxxx>]

Why do I get "WARNING: #da/0x20000 si_iosize_max=0, using DFLTPHYS." ?
Will it reduce SCSI disk performance ?

Following is the dmesg:

Copyright (c) 2003, 2004, 2005 The DragonFly Project.
Copyright (c) 1992-2003 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
	The Regents of the University of California. All rights reserved.
DragonFly 1.1-CURRENT #0: Sun Feb 20 09:05:07 GMT 2005
    root@dfbsd:/usr/src/sys/compile/gen
TSC clock: 999591866 Hz, i8254 clock: 1193098 Hz
CPU: Intel Pentium III (999.67-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x68a  Stepping = 10

Features=0x387fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,SSE>
real memory  = 536805376 (524224K bytes)
avail memory = 513785856 (501744K bytes)
Programming 24 pins in IOAPIC #0
IOAPIC #0 intpin 2 -> irq 0
DragonFly/MP: Multiprocessor motherboard
 cpu0 (BSP): apic id:  0, version: 0x00040011, at 0xfee00000
 cpu1 (AP):  apic id:  1, version: 0x00040011, at 0xfee00000
 io0 (APIC): apic id:  2, version: 0x00178011, at 0xfec00000
Preloaded elf kernel "/kernel" at 0xc049b000.
Preloaded elf module "/modules/if_fxp.ko" at 0xc049b1e8 (ignored, 
already in static kernel)
Preloaded elf module "/modules/miibus.ko" at 0xc049b290 (ignored, 
already in static kernel)
Preloaded elf module "/modules/acpi.ko" at 0xc049b338.
Pentium Pro MTRR support enabled
md0: Malloc disk
pcibios: BIOS version 2.10
Using $PIR table, 8 entries at 0xc00fdda0
npx0: <math processor> on motherboard
npx0: INT 16 interface
Using MMX optimized bcopy/copyin/copyout
acpi0: <VIA694 AWRDACPI> on motherboard
installed MI handler for int 9
acpi0: Power Button (fixed)
cpu0: <ACPI CPU (3 Cx states)> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <Host to PCI bridge> at pcibus 0 on motherboard
pci0: <PCI bus> on pcib0
IOAPIC #0 intpin 11 -> irq 2
IOAPIC #0 intpin 10 -> irq 5
IOAPIC #0 intpin 5 -> irq 10
agp0: <VIA 82C691 (Apollo Pro) host to PCI bridge> mem 
0xf0000000-0xf3ffffff at device 0.0 on pci0
pcib1: <VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 
on pci0
pci1: <PCI bus> on pcib1
pci1: <ATI model 514d graphics accelerator> at 0.0 irq 2
isab0: <VIA 82C686 PCI-ISA bridge> at device 7.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <VIA 82C686 ATA100 controller> port 0xd000-0xd00f at device 7.1 
on pci0
ata0: at 0x1f0 irq 14 on atapci0
installed MI handler for int 14
ata1: at 0x170 irq 15 on atapci0
installed MI handler for int 15
uhci0: <VIA 83C572 USB controller> port 0xd400-0xd41f irq 2 at device 
7.2 on pci0
installed MI handler for int 2
usb0: <VIA 83C572 USB controller> on uhci0
usb0: USB revision 1.0
uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1: <VIA 83C572 USB controller> port 0xd800-0xd81f irq 2 at device 
7.3 on pci0
usb1: <VIA 83C572 USB controller> on uhci1
usb1: USB revision 1.0
uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
pci0: <unknown card> (vendor=0x1106, dev=0x3057) at 7.4
fxp0: <Intel 82557 Pro/100 Ethernet> port 0xdc00-0xdc1f mem 
0xf7000000-0xf70fffff,0xf7100000-0xf7100fff irq 5 at device 9.0 on pci0
installed MI handler for int 5
miibus0: <MII bus> on fxp0
nsphy0: <DP83840 10/100 media interface> on miibus0
nsphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
fxp0: MAC address: 00:a0:c9:5a:41:98
ahc0: <Adaptec 2940 Ultra2 SCSI adapter (OEM)> port 0xe000-0xe0ff mem 
0xf7101000-0xf7101fff irq 2 at device 11.0 on pci0
aic7890/91: Ultra2 Wide Channel A, SCSI Id=7, 32/253 SCBs
pci0: <unknown card> (vendor=0x1102, dev=0x8938) at 12.0 irq 10
orm0: <Option ROMs> at iomem 0xc0000-0xc8fff,0xcc000-0xd17ff on isa0
pmtimer0 on isa0
fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0
installed MI handler for int 6
fdc0: FIFO enabled, 8 bytes threshold
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
kbd0 at atkbd0
installed MI handler for int 1
psm0: <PS/2 Mouse> irq 12 on atkbdc0
installed MI handler for int 12
psm0: model IntelliMouse, device ID 3
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
sio0: type 16550A
installed MI handler for int 4
sio1 at port 0x2f8-0x2ff irq 3 on isa0
sio1: type 16550A
installed MI handler for int 3
ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
ppc0: Generic chipset (EPP/NIBBLE) in COMPATIBLE mode
ppbus0: <Parallel port bus> on ppc0
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
installed MI handler for int 7
installed MI handler for int 0
APIC_IO: Testing 8254 interrupt delivery
APIC_IO: routing 8254 via IOAPIC #0 intpin 2
SMP: AP CPU #1 Launched!
ad0: 57241MB <ST360021A> [116301/16/63] at ata0-master UDMA100
acd0: CD-RW <SONY CD-RW CRX140E> at ata1-master PIO4
acd1: CDROM <ATAPI-CD ROM-DRIVE-52MAX> at ata1-slave PIO4
Waiting 15 seconds for SCSI devices to settle
**WARNING** waiting for the following device to finish configuring:
  xpt:	func=0xc0135d04 arg=0
Mounting root from ufs:/dev/da0s1a
da0 at ahc0 bus 0 target 0 lun 0
da0: <SEAGATE ST39173LW 5766> Fixed Direct Access SCSI-2 device
da0: 40.000MB/s transfers (20.000MHz, offset 15, 16bit), Tagged Queueing 
Enabled
da0: 8683MB (17783240 512 byte sectors: 255H 63S/T 1106C)
cd0 at ata1 bus 0 target 0 lun 0
cd0: <SONY CD-RW  CRX140E 1.0n> Removable CD-ROM SCSI-0 device
cd0: 16.000MB/s transfers
cd0: Attempt to query device size failed: NOT READY, Medium not present
cd1 at ata1 bus 0 target 1 lun 0
cd1: <ATAPI-CD ROM-DRIVE-52MAX 52AV> Removable CD-ROM SCSI-0 device
cd1: 16.000MB/s transfers
cd1: Attempt to query device size failed: NOT READY, Medium not present
WARNING: #da/0x20000 si_iosize_max=0, using DFLTPHYS.
WARNING: #da/0x20003 si_iosize_max=0, using DFLTPHYS.
WARNING: #da/0x20004 si_iosize_max=0, using DFLTPHYS.
WARNING: #da/0x20005 si_iosize_max=0, using DFLTPHYS.


---
David Xu