On Tue, 2010-06-08 at 13:10 +0800, ykzhao wrote: > On Tue, 2010-06-08 at 09:34 +0800, Matthew Garrett wrote: > > On Tue, Jun 08, 2010 at 09:28:51AM +0800, ykzhao wrote: > > > > > Does there exist the ACPI detection mechanism on the machines you > > > mentioned? If exists, does it detect the same IPMI interface with the > > > PCI IPMI detection mechanism? > > > > What is "the same"? It's not using the same ioport space, certainly. > > "The same" means that they will use the same ioport space/address. > If they use the different ioport space/address, they will be regarded as > the different IPMI device. ACPI namespace* should not be enumerating a device that is discoverable via standard PCI device enumeration so if there are multiple IPMI devices in a system, where one is enumerated via ACPI namespace and another is enumerated via PCI they should never be "the same" literal device. * I specifically denoted namespace since the ACPI SPMI table, yet another ACPI based IPMI enumeration mechanism, seems as if it could denote "the same" literal device. Matthew's approach, giving a PCI based IPMI device precedence due to its inclusion of interrupt information, does seem to have merit. Myron > > > > > > If the two mechanisms will detect the same IPMI interface, I agree with > > > what you are concerned. Do you have an idea/thought to set up the > > > relationship between ACPI and IPMI interface? In order to enable that > > > AML code can access the IPMI, it should know which IPMI interface will > > > be accessed and create the corresponding user interface. If ACPI > > > mechanism will fail to register the IPMI interface, maybe it is > > > difficult to create the correct user interface. > > > > Well, right now if you change the ordering then the PCI interface will > > never be exposed. It would be preferable to only expose the ACPI > > interface as a user-visible device if there's no prior device - if there > > is, I think the ideal solution would be for it to be an in-kernel only > > device without a corresponding UI. > > Sorry that I don't explain it clearly. The concept of "user interface" > in IPMI interface is only a channel that can be used to communicate with > the IPMI controller. It has no relationship with whether the IPMI > interface should be exposed to user space. If one driver wants to > communicate with one IPMI interface, we should create one "user > interface" firstly and send the corresponding IPMI message by using the > "user interface". > > If one IPMI interface(controller) is already detected by PCI mechanism, > then ACPI will fail to detect the same IPMI interface. In such case it > is difficult for ACPI to know which IPMI interface should be accessed > when the ACPI AML code need to communicate with the IPMI interface. > > thanks > Yakui > > > > -- Myron Stowe HP Open Source Linux Lab (OSLL) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
