On 01/19/2016 02:46 PM, Stuart_Hayes@xxxxxxxx wrote:
I'm having a problem on a number of systems where the IPMI driver isn't able to find the ACPI IPMI device. This is happening because the ACPI scan is attaching the acpi_pnp handler to the ACPI IPMI device, which is happening because the IPMI device has a _CID of PNP0C01 in addition to an _HID of IPI0001. This is a problem because acpi_scan_attach_handler() doesn't know about the IPMI drivers (ipmi_si / ipmi_ssif), which don't register as PNP or ACPI drivers, but instead expect the ACPI scan find no applicable driver and thus create a platform device.
I recently pulled out the pnp code in ipmi_si in favour of a platform device. The trouble was that you couldn't register both the ipmi_si and ipmi_ssif driver with IPI0001 (even though they were in different spaces) because IPI0001 was hard-coded into the acpi_pnp tables. This fix prevented having to update a lot of firmware.
Plus I was under the impression that this was the right thing to do, anyway. Perhaps it wasn't, but I didn't get a comment from the linux-acpi list when I submitted it (twice).
This could be fixed pretty easily by modifying acpi_scan_attach_handler() to make it return 0 without attaching a handler to devices that have a _HID of IPI0001 when the kernel has an IPMI driver available (if, say, CONFIG_IPMI_SI, CONFIG_IPMI_SI_MODULE, CONFIG_IPMI_SSIF, or CONFIG_IPMI_SSIF_MODULE are defined)... but would this be accepted?
That sounds like a bad hack to me.
Or is this something that will require reworking the IPMI drivers? Or is there another way?
The question in my mind is why the IPMI device has a _CID of PNP0C01 (or is it PNP0c01? That's the only thing I found.). From what I can tell from the spec, PNP0c01 is a "system board", and Linux has it as a "memory controller", neither of which is really applicable.
But I admit that I don't know very much about these things. I believe the right place to fix this is the driver, if we can. I'm hoping for a simple solution.
-corey -- 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
