linux-kernel - Re: [Bug 41622] [REGRESSION][BISECTED] Notebook crashes upon detecting the PCI subsystem with kernels >= 2.6.24-rc7

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Message-ID: <CAOtrxKN3sugEcNPb0MkihAJ6P+idAUfGnJBoBq_kwxsDiHdR+A@mail.gmail.com>
Date:	Wed, 24 Aug 2011 16:30:44 -0300
From:	Rogério Brito <rbrito@....usp.br>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Ivan Kokshaysky <ink@...assic.park.msu.ru>,
	Thomas Meyer <thomas@...3r.de>,
	Gary Hade <garyhade@...ibm.com>, Ingo Molnar <mingo@...e.hu>,
	Stefan Richter <stefanr@...6.in-berlin.de>,
	linux-kernel@...r.kernel.org,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	bugme-daemon@...zilla.kernel.org
Subject: Re: [Bug 41622] [REGRESSION][BISECTED] Notebook crashes upon
 detecting the PCI subsystem with kernels >= 2.6.24-rc7

Hi there, Linux, and people.

On Aug 24 2011, Linus Torvalds wrote:
> 2011/8/19 Rogério Brito <rbrito@....usp.br>:
> > Reverting the commit above with the patch below makes me able to
> > compile and run Linus's v3.1-rc2:
>
> Oh, I just noticed that the "revert" you did actually does way more than
> revert.

OK. I guess that when I bit-bisected stuff and then pulled from your tree
some conflict arised. Here is the "revert" that I could use and that works:

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 784da9d..b478c7b 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -849,14 +849,12 @@ void __ref __pci_bus_size_bridges(struct pci_bus *bus,
 		break;

 	case PCI_CLASS_BRIDGE_PCI:
+		/* don't size subtractive decoding (transparent)
+		 * PCI-to-PCI bridges */
+		if (bus->self->transparent)
+			break;
 		pci_bridge_check_ranges(bus);
-		if (bus->self->is_hotplug_bridge) {
-			additional_io_size  = pci_hotplug_io_size;
-			additional_mem_size = pci_hotplug_mem_size;
-		}
-		/*
-		 * Follow thru
-		 */
+		/* fall through */
 	default:
 		pbus_size_io(bus, 0, additional_io_size, realloc_head);
 		/* If the bridge supports prefetchable range, size it

So there are actually two changes there: what you called the "real revert"
and the second part. I can test each separately.

> The below should be totally independent, and I'd like to make sure
> that you test the revert without this change:
>
> >                pci_bridge_check_ranges(bus);
> > -               if (bus->self->is_hotplug_bridge) {
> > -                       additional_io_size  = pci_hotplug_io_size;
> > -                       additional_mem_size = pci_hotplug_mem_size;
> > -               }
> > -               /*
> > -                * Follow thru
> > -                */
> > +               /* fall through */
> >        default:
> >  -              pbus_size_io(bus);
> >  +              pbus_size_io(bus, 0, additional_io_size, add_head);
>
> And in fact I think that last line is just broken, you can't apply
> that on my current -git. What's going on?

That last line was a mistake of mine. The real changes stop at the changed
comment right before the "default:" clause of the switch.

> Also, I'd like to see the output of:
>
>  - cat /proc/iomem
>  - cat /proc/ioports
>  - /sbin/lspci -vvxxx
>
> from that machine.

OK, no problems. I'm attaching the small things here, putting at the
following URLs and will also attach them to bugzilla.

* /proc/iomem: http://paste.debian.net/127268/
* /proc/ioports: http://paste.debian.net/127269/
* lspci -vvxxx: http://paste.debian.net/127270/
* dmesg from kernel v3.1-rc3-91-ga53e77f: http://paste.debian.net/127271/
* the pseudo-revert: http://paste.debian.net/127272/
* acpidump: http://paste.debian.net/127275/
* dmidecode: http://paste.debian.net/127276/

> And Bjorn asked for a full dmesg, and I see that email, but it didn't get
> updated into the bugzilla entry (apparently bugzilla is not smart enough
> to take email attachments and make them bugzilla attachments). Rogério,
> can you do that so that it doesn't get lost?

Sure. Anything you ask me.


Thanks,

-- 
Rogério Brito : rbrito@...e.usp.br,gmail.com} : GPG key 4096R/BCFCAAAA
http://rb.doesntexist.org : Packages for LaTeX : algorithms.berlios.de
DebianQA: http://qa.debian.org/developer.php?login=rbrito%40ime.usp.br

View attachment "proc-iomem.txt" of type "text/plain" (1627 bytes)

View attachment "proc-ioports.txt" of type "text/plain" (1168 bytes)

View attachment "lscpi-vvxxx.txt" of type "text/plain" (47822 bytes)

View attachment "pseudo-revert.patch" of type "text/x-diff" (769 bytes)