Bug 8772

Summary:	PCI: Bus #07 (-#0a) is hidden behind transparent bridge #06 (-#07)
Product:	Drivers	Reporter:	Marco Rodrigues (gothicx)
Component:	PCI	Assignee:	Bernhard Kaindl (bk)
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	bunk, greg
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.22	Subsystem:
Regression:	---	Bisected commit-id:
Attachments:	dmesg lspci

Description Marco Rodrigues 2007-07-17 07:06:11 UTC

Most recent kernel where this bug did not occur:
Distribution: Ubuntu Gutsy
Hardware Environment: ACER Aspire 5633WLMi
Software Environment:
Problem Description:

PCI quirk: region 1000-107f claimed by ICH6 ACPI/GPIO/TCO
PCI quirk: region 1180-11bf claimed by ICH6 GPIO
PCI: Transparent bridge - 0000:00:1e.0
PCI: Bus #07 (-#0a) is hidden behind transparent bridge #06 (-#07) (try 'pci=assign-busses')
Please report the result to linux-kernel to fix this permanently

Steps to reproduce: Just check /var/log/messages to see this message to report it.

Comment 1 Marco Rodrigues 2007-07-17 07:07:23 UTC

Created attachment 12063 [details]
dmesg

This is the dmesg after run the kernel with parameter pci=assign-busses

Comment 2 Marco Rodrigues 2007-07-17 07:07:53 UTC

Created attachment 12064 [details]
lspci

Comment 3 Marco Rodrigues 2007-07-17 07:09:42 UTC

Comment on attachment 12064 [details]
lspci

This is the lspci -vvnn after run the kernel with parameter pci=assign-busses

Comment 4 Marco Rodrigues 2007-07-17 12:16:17 UTC

https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/99960

One more :-) I don't know if it's fixed on 2.6.22.1

Comment 5 Marco Rodrigues 2007-07-30 14:35:14 UTC

When it will be added to the kernel ?

Comment 6 chris kelley 2007-08-03 18:25:47 UTC

I just compiled 2.6.22.1 and it's still present. I've got a Dell D630 with seemingly 200 usb ports. pci=assign-busses suppressed the problem in my case as well. My distribution is kubuntu 7.04 amd64 alternate cd. In learning about the compile options, I learned that the Intel 945GM chipset is a strange hybrid of the i810 family, with a lot of 82801 ICH8 family chipsets driving other things. It appears as though the ICH8 is new and I suspect most existing code is great for ICH6 and 7.

from dmesg:
PCI: Transparent bridge - 0000:00:1e.0 
PCI: Bus #04 (-#07) is hidden behind transparent bridge #03 (-#04) (try 'pci=assign-busses')
...
PCI: Bus 4, cardbus bridge: 0000:03:01.0

from lspci:
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f2)
04:01.0 CardBus bridge: O2 Micro, Inc. Cardbus bridge (rev 21)

** hmmmm, error calls the cardbus 03:01.0 when it is 04:01.0 in lspci **

After the pci=assign-buses, the cardbus pci address is correct and there are no complaints about the PCI bridge:
PCI: Bus 5, cardbus bridge: 0000:04:01.0
PCI: Bridge: 0000:00:1e.0

:)

Comment 7 Marco Rodrigues 2007-08-31 04:24:21 UTC

With kernel 2.6.22.6 - "PCI: lets kill the 'PCI hidden behind bridge' message", this bug should be set to invalid ?

Comment 8 Bernhard Kaindl 2007-10-16 06:32:18 UTC

Yes, it's closed now.

Is was a warning which I left in to be sure that the reason for it is properly dealt with, but we removed it from the normal user's sight now because we found

* that the PCI misconfiguration which is being indicated in this message only
  seems to be an issue with CardBus and
* that the CardBus fixup code which we have in place since 2.6.18 with appears
  to be sufficient.

Thus, I submitted a patch which was merged mainline with 2.6.22.6 and 2.6.23
that turns it into a message which is only enabled when debugging PCI, so in
practical users terms, the warning is gone. 


*** This bug has been marked as a duplicate of bug 7531 ***