Messages in this thread | | | From | Bjorn Helgaas <> | Subject | Re: New conflict message in latest GIT | Date | Wed, 23 Jul 2008 12:56:42 -0600 |
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On Tuesday 22 July 2008 12:56:36 pm Fabio Comolli wrote: > Linus' GIT tree 2.6.26-05752-g93ded9b shows this message: > > i801_smbus 0000:00:1f.3: PCI INT B -> GSI 19 (level, low) -> IRQ 19 > ACPI: I/O resource 0000:00:1f.3 [0x18e0-0x18ff] conflicts with ACPI > region SMBI [0x18e0-0x18ef] > ACPI: Device needs an ACPI driver > > There is no equivalent in 2.6.26 or previous kernels.
The "ACPI: I/O resource ... conflicts with ..." message was added by Thomas: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=df92e695998e1bc6e426a840eb86d6d1ee87e2a5
That conflict checking infrastructure was in 2.6.26, but Jean's change to make the i801_smbus driver use it didn't happen until about a week ago: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=54fb4a05af0a4b814e6716cfdf3fa97fc6be7a32
The message is telling us that the i801_smbus driver thinks it owns the 0x18e0-0x18ff region, but there's also an ACPI opregion that references that region. There's no coordination between ACPI and the i801_smbus driver, so there may be issues where nearly simultaneous accesses cause incorrect behavior, e.g,. one may read the wrong value from a temperature sensor. That, of course, can lead to more serious things like unintended machine shutdowns.
I don't have any ideas about how to address this. I think Thomas's intent was to collect better information for unreproducible bugs. (Maybe this sort of conflict should even set a taint flag?)
Bjorn
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