On Tuesday, May 19, 2015 08:42:00 AM Jarod Wilson wrote: > On 5/19/2015 7:43 AM, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > 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 <jarod@xxxxxxxxxx> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > --- > > > > 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, Right, just sent an updated patch. > but I made more or less the exact same > changes here, and am about to give them a spin on the ZBook 17. Cool, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
