Bug 15361 - nForce2_smbus conflicts with ACPI region SM00
nForce2_smbus conflicts with ACPI region SM00
Product: ACPI
Classification: Unclassified
Component: Config-Other
All Linux
: P1 low
Assigned To: ykzhao
Depends on:
  Show dependency treegraph
Reported: 2010-02-20 09:11 UTC by argos66
Modified: 2010-09-29 02:01 UTC (History)
3 users (show)

See Also:
Kernel Version: 2.6.32
Tree: Mainline
Regression: No

dmesg (43.91 KB, text/plain)
2010-02-20 09:20 UTC, argos66

Description argos66 2010-02-20 09:11:35 UTC

I have this couple of line in my dmesg (more complete dmesg are in attachment).

[   11.171119] i2c i2c-0: nForce2 SMBus adapter at 0x1c00
[   11.171124] ACPI: I/O resource nForce2_smbus [0x1c40-0x1c7f] conflicts with ACPI region SM00 [0x1c40-0x1c45]
[   11.171191] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver
[   11.171193] nForce2_smbus 0000:00:01.1: Error probing SMB2.

#uname -a
Linux argos-lnx 2.6.32-13-generic #18-Ubuntu SMP Wed Feb 10 21:32:38 UTC 2010 x86_64 GNU/Linux

#dmidecode --type baseboard
# dmidecode 2.9
SMBIOS 2.4 present.

Handle 0x0002, DMI type 2, 8 bytes
Base Board Information
	Manufacturer: ASUSTeK Computer INC.
	Product Name: M2N-SLI DELUXE
	Version: 1.XX
	Serial Number: 123456789000

Many people have the same bug on differents motherboard (look at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/440780)

Comment 1 argos66 2010-02-20 09:20:58 UTC
Created attachment 25129 [details]
Comment 2 ykzhao 2010-02-22 01:06:19 UTC
   The corresponding I/O port(0x1C40-0x1c45) will be accessed by ACPI. If we still load the nforce2_smbus driver, they will access the same I/O port. As there is no synchronization between smbus driver and ACPI, maybe the system can't work well. So when the resource conflict is detected, we had better not load the corresponding nforce2_smbus driver.

    If you think that nforce2_smbus driver is very important, you can add the boot option of "acpi_enforce_resources=lax". Of course the warning message still exists. But it can be loaded.

Comment 3 ykzhao 2010-02-22 01:11:34 UTC
The warning message does the right thing. It only reminds that the nforce2_smbus driver had better not be loaded as there exists the potential conflict between ACPI and SMbus driver.

Comment 4 Zhang Rui 2010-02-22 05:50:18 UTC
is there anything bad together with this message?
for example, are there any devices that fail to work in 2,6,32, compared with 2.6.30/31?
Comment 5 argos66 2010-02-22 07:19:58 UTC
Thanks for your responses.

This problem exists in 2.6.30 and 2.6.31.
This message don't block the system or other, but it's for have a cleanup boot log.


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