PCI Config on Intel 855 chip after resume

[Peter Clifton]

Hi,

Is it normal for the PCI config space to be changed after a resume from
S3 such that memory regions are disabled?

I'm (remotely) debugging this issue:

very corrupt X after suspend/resume
https://bugs.launchpad.net/bugs/133118


And noticed that an lspci before  / after suspend shows a diff:

--- lspci6.txt  2007-10-17 15:01:33.000000000 +0100
+++ lspci7.txt  2007-10-17 15:01:33.000000000 +0100
@@ -39,10 +39,10 @@
 00:02.1 Display controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
        Subsystem: Hewlett-Packard Company Unknown device 08bc
        Flags: bus master, fast devsel, latency 0
-       Memory at a0000000 (32-bit, prefetchable) [size=128M]
-       Memory at 90480000 (32-bit, non-prefetchable) [size=512K]
+       Memory at a0000000 (32-bit, prefetchable) [disabled] [size=128M]
+       Memory at 90480000 (32-bit, non-prefetchable) [disabled] [size=512K]
        Capabilities: <access denied>
-00: 86 80 82 35 07 00 90 00 02 00 80 03 00 00 80 00
+00: 86 80 82 35 04 00 90 00 02 00 80 03 00 00 80 00
 10: 08 00 00 a0 00 00 48 90 00 00 00 00 00 00 00 00
 20: 00 00 00 00 00 00 00 00 00 00 00 00 3c 10 bc 08
 30: 00 00 00 00 d0 00 00 00 00 00 00 00 00 00 00 00
@@ -91,7 +91,7 @@
        Memory behind bridge: 90000000-903fffff
        Prefetchable memory behind bridge: 40000000-47ffffff
 00: 86 80 48 24 07 01 80 80 81 00 04 06 00 00 01 00
-10: 00 00 00 00 00 00 00 00 00 01 06 20 30 30 80 02
+10: 00 00 00 00 00 00 00 00 00 01 06 20 30 30 80 22
 20: 00 90 30 90 00 40 f0 47 00 00 00 00 00 00 00 00
 30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00


This is inspite an ubuntu suspend / resume script which tries to save
and restore the config space for video devices around suspend
operations.

Any ideas?

-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)