Bug 8899

Summary:	PCI: Bus #04 (-#07) is hidden behind transparent bridge #03 (-#04)
Product:	Drivers	Reporter:	Bogdan (bogdanb+kernel)
Component:	PCI	Assignee:	Bernhard Kaindl (bk)
Status:	RESOLVED DUPLICATE
Severity:	low	CC:	bunk, greg
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.22	Subsystem:
Regression:	---	Bisected commit-id:
Attachments:	Dmesg before setting assign-busses (this asks for the report) Dmesg after setting pci=assign-busses Results of "lspci -vvv" (with pci=assign-busses set)

Description Bogdan 2007-08-17 07:44:37 UTC

Distribution: Ubuntu Gutsy
Hardware Environment: Dell Latitude D620
Software Environment: Linux cimer 2.6.22-9-generic #1 SMP Fri Aug 3 00:50:37 GMT 2007 i686 GNU/Linux
Problem Description:

I've got the following messages in dmesg:
PCI: Bus #04 (-#07) is hidden behind transparent bridge #03 (-#04) (try 'pci=assign-busses')
Please report the result to linux-kernel to fix this permanently

So here is the report. Attachments to follow.

Comment 1 Bogdan 2007-08-17 07:46:16 UTC

Created attachment 12425 [details]
Dmesg before setting assign-busses (this asks for the report)

Comment 2 Bogdan 2007-08-17 07:46:57 UTC

Created attachment 12426 [details]
Dmesg after setting pci=assign-busses

Comment 3 Bogdan 2007-08-17 07:48:00 UTC

Created attachment 12427 [details]
Results of "lspci -vvv" (with pci=assign-busses set)

Comment 4 Bogdan 2007-08-17 08:06:04 UTC

I've seen similar bugs, including http://bugzilla.kernel.org/show_bug.cgi?id=8074 and http://bugzilla.kernel.org/show_bug.cgi?id=8591

I'm not sure I understand the comments of Bernhard Kaindl. Is this just a "leftover" warning that should be removed (thus the reports are mostly useless), or is there actually an issue?

Comment 5 Bogdan 2007-08-17 08:06:52 UTC

Oh, and another question: should I leave the pci=assign-busses set or not?

Comment 6 Bernhard Kaindl 2007-10-16 06:30:14 UTC

Is this just 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.
* 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 ***