On 5/19/2015 7:43 AM, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Jarod Wilson reports that the expresscard hotplug setup doesn't work
on HP ZBook G2. The problem turns out to be the ACPI-based "slot
detection" code called from pciehp_probe() which tries to use some
questionable heuristics based on what ACPI objects are present for
the PCIe port device at hand to figure out whether or not to register
a hotplug slot for that port.
That code is used if there is at least one PCIe port having an ACPI
device configuration object related to hotplug (such as _EJ0 or _RMV)
and the Thunderbolt port on the affected machine has _RMV. Of course,
Thunderbolt and PCIe native hotplug need not be mutually exclusive
(as they aren't on the machine in question), so that rule is simply
incorrect.
Moreover, the ACPI-based "slot detection" check does not add any
value if pciehp_probe() is called at all and the service type of the
device object it has been called for is PCIE_PORT_SERVICE_HP, because
PCIe hotplug services are only registered if the _OSC handshake in
acpi_pci_root_add() allows the kernel to control the PCIe native
hotplug feature. No more checks need to be carried out to decide
whether or not to register a native PCIe hotlug slot in that case.
For the above reasons, make pciehp_probe() check if it has been
called for the right service type and drop the pointless ACPI-based
"slot detection" check from it. Also remove the entire code whose
only user is that check (the entire pciehp_acpi.c file goes away
as a result) and drop function headers related to it from the
internal PCIeHP header file.
Link: http://marc.info/?t=143163219300002&r=1&w=2
Link: https://bugzilla.kernel.org/show_bug.cgi?id=98581
Reported-by: Jarod Wilson <ja...@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
---
Bjorn, that's -stable material I think. It should be applicable at least
since commit 5ba113f7c4fb (PCI: acpiphp: Handle PCIe ports without native
hotplug capability) that was shipped in 3.10.
Thanks!
I believe you also want to rip the pciehp_acpi.o hunk out of
drivers/pci/hotplug/Makefile, but I made more or less the exact same
changes here, and am about to give them a spin on the ZBook 17.
--
Jarod Wilson
ja...@redhat.com
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