On 6/11/2015 1:05 PM, Jarod Wilson wrote:
On 5/21/2015 9:21 PM, Rafael J. Wysocki wrote:
On Thursday, May 21, 2015 11:11:46 AM Bjorn Helgaas wrote:
On Tue, May 19, 2015 at 03:27:58PM +0200, 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>
This is awesome! Applied to pci/hotplug for v4.2, with Jarod's
reviewed/tested-by.
Thanks!
Looks like I didn't test enough. I can't explain WHY, but with this
applied, now thunderbolt hot unplug of a network adapter goes haywire,
where prior to the patch, it worked just fine. Still looking into it...
Filed bug, dmesg spew can be found in the bug.
https://bugzilla.kernel.org/show_bug.cgi?id=99841
--
Jarod Wilson
jarod@xxxxxxxxxx
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