Messages in this thread | | | Date | Sat, 9 Aug 2008 18:32:31 +0200 | From | "Fabio Comolli" <> | Subject | Re: New conflict message in latest GIT |
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Hi Jean.
On Sat, Aug 9, 2008 at 6:13 PM, Jean Delvare <khali@linux-fr.org> wrote: > Hi Fabio, > > On Wed, 23 Jul 2008 21:50:24 +0200, Fabio Comolli wrote: >> Hi. >> >> On Wed, Jul 23, 2008 at 8:56 PM, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote: >> > 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?) > > Yes, at this point these messages are informative only and displayed as > a hint when investigating bug reports. In the long run, we might > decide to grant exclusive access to the shared region to either ACPI or > the native driver, or to setup a safe concurrent access mechanism. > That's a long way to go though, due to the diversity of BIOSes out > there and the fact that many of them declare opregions in bogus ways. > >> OK, I actually didn't even know what i801_smbus (i2c_801 I suppose) >> was. It seems that my laptop has a super-IO chip which is detected by >> lm-sensors as `Nat. Semi. PC87591 Super IO' which doesn't have a >> driver and never will. >> >> So, if I'm correct, this modules is totally useless for me and I >> better compile it out. Am I correct? > > Yes you are. If you don't need i2c-i801 on this machine, best is to not > build it or to prevent it from loading. Or you can boot with > acpi_enforce_resources=strict to prevent the i2c-i801 driver from > attaching to the device. >
Ok, thanks for confirming it.
> I am a bit curious though, why ACPI would declare an opregion for a > device that isn't used. Might be yet another case of BIOS copied from > another machine and not cleaned up appropriately. >
Well, you should ask HP for that :-)
Anyway, as usual linux is not supported at all on this laptop, it came with XP. One thing that puzzles me is why bothering adding a monitoring chip for which drivers do not exist for any OS?
> -- > Jean Delvare >
Regards, Fabio
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