Date:	Fri, 6 Jul 2012 14:38:14 -0600
From:	Bjorn Helgaas <bhelgaas@...gle.com>
To:	Kamil Grzebien <ciptok@...il.com>
Cc:	Stanislaw Gruszka <sgruszka@...hat.com>, linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-wireless@...r.kernel.org,
	Yinghai Lu <yinghai@...nel.org>
Subject: Re: Initializing iwl3945 error

On Mon, Jul 2, 2012 at 2:49 PM, Kamil Grzebien <ciptok@...il.com> wrote:
> On Mon, Jul 2, 2012 at 6:31 AM, Stanislaw Gruszka <sgruszka@...hat.com> wrote:
>> On Sun, Jul 01, 2012 at 07:01:58PM +0100, Kamil Grzebien wrote:
>>> I haven't tried your patch yet, but wanted to share with one thing.
>>> Currently I use new kernel 3.4.3, where the problem doesn't exist
>>> anymore. However I still would like to know what was the cause and
>>> which change brought the solution. Is there anything which comes to
>>> your mind in terms of recent changes in kernel? I also added logs from
>>> the newest kernel, so it might be easier for track it.
>>
>> Below is the diff from working kernel and non working kernel.
>> You are using PAE kernel what influence PCI mappings. Is this fixed also
>> on 3.4 non-PAE kernel?
>
> The problem is also fixed in non-PAE kernel. I've attached the logs
> from that kernel also. Besides that currently I was comparing both PAE
> kernels installed on my machine - kernel 3.3.7 (problem exist) and
> kernel 3.4.3 (problem solved). There must be something that has
> changed either in the code or maybe kernel configuration!?

I compared your 3.3.0 and 3.4.3 logs:

    -Linux version 3.3.0-4.fc16.i686
(mockbuild@...-04.phx2.fedoraproject.org) gcc version 4.6.2 20111027
(Red Hat 4.6.2-1) (GCC) ) #1 SMP Tue Mar 20 18:45:14 UTC 2012
    +Linux version 3.4.3-1.fc17.i686
(mockbuild@...-04.phx2.fedoraproject.org) gcc
version 4.7.0 20120507 (Red Hat 4.7.0-5) (GCC) ) #1 SMP Mon Jun 18
20:52:37 UTC 2012

I don't see much that's different, except this:

    -pci 0000:03:09.1: reg 10: [mem 0xf1bff400-0xf1bff4ff]
    +pci 0000:03:09.1: reg 10: [mem 0xf1bff500-0xf1bff5ff]

which hints that the BIOS configured that device (an SD Host
controller) differently.  Is it possible that a BIOS setup change is
what made the difference?  Can you reproduce the failure and success
on the exact same hardware & BIOS setup?  I also notice the 3.3.0
failure was apparently on battery power and the 3.4.3 success was with
AC power.  Shouldn't matter, but obviously *something* that shouldn't
matter does matter in this case.

The problem device is 0000:0b:00.0, and the bridge 00:1c.1 leads to
bus 0b.  There's a little bit more noise in 3.4.3 related to 1c.1
bridge windows, but the ultimate configuration is the same except for
the 64-bit pref window, which 0b:00.0 doesn't use anyway:

 pci 0000:0b:00.0: reg 10: [mem 0xf1eff000-0xf1efffff]
-pci 0000:00:1c.1: BAR 15: assigned [mem 0xf0200000-0xf03fffff 64bit pref]
+pci 0000:00:1c.1: bridge window [io  0x1000-0x0fff] to [bus 0b-0b]
add_size 1000
+pci 0000:00:1c.1: bridge window [mem 0x00100000-0x000fffff 64bit pref] to [bus
0b-0b] add_size 200000
+pci 0000:00:1c.1: res[15]=[mem 0x00100000-0x000fffff 64bit pref]
get_res_add_size add_size 200000
+pci 0000:00:1c.1: res[13]=[io  0x1000-0x0fff] get_res_add_size add_size 1000
+pci 0000:00:1c.1: BAR 15: assigned [mem 0xf0400000-0xf05fffff 64bit pref]
 pci_bus 0000:0b: resource 1 [mem 0xf1e00000-0xf1efffff]
-pci_bus 0000:0b: resource 2 [mem 0xf0200000-0xf03fffff 64bit pref]
+pci_bus 0000:0b: resource 2 [mem 0xf0400000-0xf05fffff 64bit pref]

Any ideas, Yinghai?

Bjorn
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