IRQ 16-19 - damn ACPI under W2k ?!

[reondee]

Hey Guys!

My System
Gigabyte GA-6BXD
2x PIII 450MHz
2x Seagate Barracuda 17,1 GB U160-Scsi
Adaptec U160
512MB PC100 Memory
Matrox G400 Max
SB AWE32 ISA
AVM Fritz! Card PCI
Level One 10/100 Network Adapter
Plextor 40x CD-Rom SCSI
Plextor 12x CD-RW-Recorder SCSI
Windows 2000 SP1 as OS
MY Problem:
Well my System runs nearly flawlessly... ok some Application-crash sometimes but the System never hangs up, no bsod or systemcrash since 9 month.
BUT when I look in the IRQ List of the MMC in Windows, I can't believe it: It shows the following IRQ list (REMEMBER: Physically there are only 15 IRQ available)

Network IRQ 18
SCSI IRQ 17
G400 MAX IRQ 16
ISDN IRQ 19
USB IRQ 19

So I suppose, that is a Windows-failure. I think every card has its own IRQ but the wrong number is displayed, because the bios while booting shows me that every card has its own IRQ and isdn shares it with USB. So it's nearly the same as in Windows - only the numbers are different. What do you think? Whats wrong or can't I correct this because it's a bug in Windows?

Thx in a advance

[Greebe]

That's not an error, but a properly functioning system running in ACPI mode under Win2K.

[reondee]

COOOOL! Thank you, so I can stay quite!

[dZeus]

they are called 'virtual IRQs'...
somehow I don't get them in Win2k, not that I mind... a flatmate who also has a Abit BX motherboard (a BP6) does get them.

I thought the G400 had some trouble running on virtual IRQs... maybe not?

[Chucky Cheese]

...my system has these virtual irqs' also, but they go alot higher;

System Information report written at: 11/24/2000 09:19:37 PM
[IRQs]

IRQ Number Device
128 Matrox Millennium G400 DualHead - English
31 Intel 82371AB/EB PCI to USB Universal Host Controller
48 Symbios 22910, 21002 PCI SCSI Adapter; 53C896 Device
49 Symbios 22910, 21002 PCI SCSI Adapter; 53C896 Device
64 Creative SB Live! (WDM)
68 3Com EtherLink 10/100 PCI NIC with 3XP Processor (3CR990-TX-95)
1 PC/AT Enhanced PS/2 Keyboard (101/102-Key)
4 Communications Port (COM1)
3 Communications Port (COM2)
6 Standard floppy disk controller
8 System CMOS/real time clock
13 Numeric data processor
12 Logitech PS/2 Port Mouse

haven't had any problems!!! i have a gx chipset that is not acpi compliant.

cc

[DentyCracker]

aren't those high irqs a result of the Dual processor config?
I seem to remember something like that on my friend's Tyan Tiger 100 with dual P!!! 450s

[Dyre]

The dual pIII, serverworks chipset, Supermirco board went up to like 30 or something, and i only had a couple devices on it.

Really supprised me, as i had never seen anything like that before.

[DosFreak]

It's normal. If your bios has an improper ACPI implementation then you may experience problems. If you don't have any probs then leave it alone.

[kjliew]

In Win2k DP configuration, the interrupts are no longer handled by legacy chained dual-8259A. They are handled by the IOAPIC. IOAPIC may have 15 or more IRQs.

I don't think there is something called "virtual IRQ" in Win2k, or is it related to ACPI. If you get unbelievable high IRQ number like 255, then it's a bug in Win2k. Microsoft has already published the article in the knowledge base. Win2k has problem with MPS 1.4 table, and uses the wrong field in the table to report IRQ usage. The article also describes complete steps to troubleshoot IRQ conflicts in DP config where such situation may arise.

Even for UP config, you can still get this bug if the BIOS has enabled IOAPIC and constructed MPS 1.4 table.

MPS Uniprocessor HAL
MPS Multiprocessor HAL
ACPI Multiprocessor HAL
All these 3 HALs use IOAPIC. And if MPS 1.4 table is used, wrong and unbelievable high IRQ number will be reported in Device Manager.

ACPI Uniprocessor HAL
It depends if it's in legacy PIC mode or IOAPIC.

Standard PC HAL.
No problem here, always uses legacy PIC.



[This message has been edited by kjliew (edited 25 November 2000).]

[Chucky Cheese]

...what is odd is that at the bios level(..post configuration screen) my irqs' are as follows;

IRQ DEVICE

5 USB
9 SBLIVE
10 SCSI
11 AGP/VGA
14 ETHERNET
15 SCSI

i have a "compatability" flag in my bios called..acpi aware os - yes/no..set to yes. changing it makes no difference in win2k installation irq assignments. i do know that this board is mps 1.4 compliant. i did however try a fresh install of win2k using the F5 function and selecting the acpi hal...i didn't make it past disk 4, from the boot floppy installation.

cc

[reondee]

ORIGINAL POST:
In Win2k DP configuration, the interrupts are no longer handled by legacy chained dual-8259A. They are handled by the IOAPIC. IOAPIC may have 15 or more IRQs.
I don't think there is something called "virtual IRQ" in Win2k, or is it related to ACPI. If you get unbelievable high IRQ number like 255, then it's a bug in Win2k. Microsoft has already published the article in the knowledge base. Win2k has problem with MPS 1.4 table, and uses the wrong field in the table to report IRQ usage. The article also describes complete steps to troubleshoot IRQ conflicts in DP config where such situation may arise.
Even for UP config, you can still get this bug if the BIOS has enabled IOAPIC and constructed MPS 1.4 table.

MPS Uniprocessor HAL
MPS Multiprocessor HAL
ACPI Multiprocessor HAL
All these 3 HALs use IOAPIC. And if MPS 1.4 table is used, wrong and unbelievable high IRQ number will be reported in Device Manager.

ACPI Uniprocessor HAL
It depends if it's in legacy PIC mode or IOAPIC.

Standard PC HAL.
No problem here, always uses legacy PIC.


[This message has been edited by kjliew (edited 25 November 2000).]


So it becames not quite clear for me if a IRQ up to 20 is normal with ACPI enabled or not - cuz you said that ACPI can have more than 15 IRQ. I must add that I have already run my System with only one cpu and the uniprocessor HAl was enabled - same results, same Interrupts.
I never saw IRQs like 240 or so - I think its one of thousands Win-Bugs.
So have you any suggestions which way I should go.
Thx
[reondee]

[Rags]

Chucky Cheese,


Virtual IRQ's are a normal happening in NT, don't sweat it.

Rags

[kjliew]

Repeat, it is NOT ACPI problem, it's the MPS 1.4 table that Win2k has problem with.

Read my post again, even on uniprocessor, if you install MPS Uniprocessor HAL, ACPI Uniprocessor HAL, there are still chances that MPS 1.4 table being used.

IRQ of 20 can be normal. As far as I know, certain IOAPIC has IRQ up to 24.

On the other hand, if you install Standard PC HAL, there will not be any IRQ more than 15, because Standard PC uses legacy chained dual-8259A for interrupt handling.