PCI BIOS Bug messages

PCI BIOS Bug messages

[Vasudevan S]

I run Fedora Core 6 on the 'compaq nc6320' laptop. I am using the
'2.6.19.1' kernel.

While booting the kernel, I noticed the following error message:

PCI: BIOS Bug: MCFG area at f8000000 is not E820-reserved
PCI: Not using MMCONFIG.

After some search, I commented out the 'e820_all_mapped()' check in
the 'pci_mmcfg_init()' function. I no longer see this message and MMCONFIG
method seems to be used now.

Is this the right thing to do?

Thanks,
--Vasu

lspci output on this laptop:

00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS/940GML and
945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile
945GM/GMS/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/940GML
Express Integrated Graphics Controller (rev 03)
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High
Definition Audio Controller (rev 01)
00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express
Port 1 (rev 01)
00:1c.2 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express
Port 3 (rev 01)
00:1c.3 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express
Port 4 (rev 01)
00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
UHCI #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
UHCI #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
UHCI #3 (rev 01)
00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
UHCI #4 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2
EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface
Bridge (rev 01)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
Controller (rev 01)
00:1f.2 SATA controller: Intel Corporation 82801GBM/GHM (ICH7 Family)
Serial ATA Storage Controller AHCI (rev 01)
01:00.0 Network controller: Broadcom Corporation Dell Wireless 1390
WLAN Mini-PCI Card (rev 01)
04:06.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
04:06.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant
IEEE 1394 Host Controller
04:06.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia
Card Reader (SD/MMC/MS/MS PRO/xD)
04:06.3 Class 0805: Texas Instruments PCIxx12 SDA Standard Compliant
SD Host Controller
04:06.4 Communication controller: Texas Instruments PCIxx12 GemCore
based SmartCard controller
04:0e.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5788
Gigabit Ethernet (rev 03)

Re: PCI BIOS Bug messages

[Robert Hancock]

Vasudevan S wrote:
> I run Fedora Core 6 on the 'compaq nc6320' laptop. I am using the
> '2.6.19.1' kernel.
> 
> While booting the kernel, I noticed the following error message:
> 
> PCI: BIOS Bug: MCFG area at f8000000 is not E820-reserved
> PCI: Not using MMCONFIG.
> 
> After some search, I commented out the 'e820_all_mapped()' check in
> the 'pci_mmcfg_init()' function. I no longer see this message and MMCONFIG
> method seems to be used now.
> 
> Is this the right thing to do?

Maybe on that box you can get away with it, but I believe the purpose of 
the check is to weed out BIOSes that have totally broken MCFG tables. I 
think there is some work going on to be able to check and/or bash the 
chipset registers manually on various chipsets to reduce our reliance on 
the BIOS getting this right..

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/