Messages in this thread | | | Date | Mon, 18 May 2015 12:17:23 -0400 | From | Jarod Wilson <> | Subject | Re: [PATCH] pci/hotplug: work-around for missing _RMV on HP ZBook G2 |
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On 5/18/2015 10:33 AM, Jarod Wilson wrote: > On 5/17/2015 8:26 PM, Rafael J. Wysocki wrote: >> On Saturday, May 16, 2015 09:41:55 AM Bjorn Helgaas wrote: >>> On Sat, May 16, 2015 at 09:37:50AM -0500, Bjorn Helgaas wrote: >>>> Hi Jarod, >>>> >>>> On Thu, May 14, 2015 at 03:33:58PM -0400, Jarod Wilson wrote: >>>>> The HP ZBook 15 and 17 Mobile Workstations, generation 2, up to and >>>>> including at least BIOS revision 01.07, do not have an ACPI _RMV >>>>> object >>>>> associated with their expresscard slots, so acpi-based hotplug-capable >>>>> slot detection fails. If we fall back to pcie-based detection, the >>>>> systems >>>>> work just fine, so this uses dmi matching to do that. With luck, a >>>>> future >>>>> BIOS will remedy this (I've let someone at HP know about the problem), >>>>> but for now, just use this for all existing versions. > ... >>>> Oh, my goodness. I forgot how terrible this path is. Can anyone >>>> write a >>>> simple explanation of how we choose to use acpiphp or pciehp? >> >> In theory, that should depend on the _OSC handshake in >> acpi_pci_root_add(). >> >> If the firmware doesn't give us control of the PCIe features, we'll >> not use >> pciehp (or at least that's the idea). >> >> acpiphp is used if pciehp doesn't claim the device, AFAICS. > > [ 4.013326] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM > ClockPM Segments MSI] > [ 4.015860] acpi PNP0A08:00: _OSC: OS now controls [PCIeHotplug PME > AER PCIeCapability] > > So at a glance, it would appear that pciehp *should* be claiming it, > right? Something I noted in the bug I filed is that the device ID > reported there is PNP0A08, and the root_device_id table that associates > with acpi_pci_root_add() only includes PNP0A03 in it. Is that correct, > or should 08 also be in there, which might remedy this? (I can test this > out easily enough).
Nope, makes no difference, seems those are just two different references to the same bus, based on a peek at the extracted dsdt:
Name (_HID, EisaId ("PNP0A08") /* PCI Express Bus */) // _HID: Hardware ID Name (_CID, EisaId ("PNP0A03") /* PCI Bus */) // _CID: Compatible ID
-- Jarod Wilson jarod@redhat.com
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