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| author |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-05-19 15:27:58 +0200 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2015-05-21 11:01:12 -0500 |
| commit | e705c2959b06b9db184842852da619a0b1672bbc (patch) | |
| tree | 420a6a73f9ae44aacd5cd1e8f4e85870469cd8b0 /drivers/pci/hotplug/Makefile | |
| parent | Linux 4.1-rc2 (diff) | |
| download | wireguard-linux-e705c2959b06b9db184842852da619a0b1672bbc.tar.xz wireguard-linux-e705c2959b06b9db184842852da619a0b1672bbc.zip | |
PCI: pciehp: Drop pointless ACPI-based "slot detection" check
Jarod Wilson reports that ExpressCard hotplug doesn't work on HP ZBook G2.
The problem turns out to be the ACPI-based "slot detection" code called
from pciehp_probe() which uses questionable heuristics based on what ACPI
objects are present for the PCIe port device to figure out whether 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 ZBook has _RMV. Of course, Thunderbolt and PCIe
native hotplug need not be mutually exclusive (as they aren't on the
ZBook), 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://lkml.kernel.org/r/1431632038-39917-1-git-send-email-jarod@redhat.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=98581
Reported-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Diffstat (limited to 'drivers/pci/hotplug/Makefile')
| -rw-r--r-- | drivers/pci/hotplug/Makefile | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile index 4a9aa08b08f1..b616e7588ff4 100644 --- a/drivers/pci/hotplug/Makefile +++ b/drivers/pci/hotplug/Makefile @@ -61,9 +61,6 @@ pciehp-objs := pciehp_core.o \ pciehp_ctrl.o \ pciehp_pci.o \ pciehp_hpc.o -ifdef CONFIG_ACPI -pciehp-objs += pciehp_acpi.o -endif shpchp-objs := shpchp_core.o \ shpchp_ctrl.o \ |