From: Jarod Wilson <jarod@redhat.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-kernel@vger.kernel.org, Len Brown <lenb@kernel.org>,
linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [Update][PATCH] PCIe / hotplug: Drop pointless ACPI-based "slot detection" check
Date: Tue, 19 May 2015 10:40:39 -0400 [thread overview]
Message-ID: <555B4B67.40203@redhat.com> (raw)
In-Reply-To: <1573807.HQlNd2BFYP@vostro.rjw.lan>
On 5/19/2015 9:27 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@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 <jarod@redhat.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>
> Changes in Makefile were missing from the previous version.
>
> 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!
Changes all look good to me, and they work perfectly here with the
previously problematic ZBook 17.
Reviewed-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
--
Jarod Wilson
jarod@redhat.com
next prev parent reply other threads:[~2015-05-19 14:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-14 19:33 [PATCH] pci/hotplug: work-around for missing _RMV on HP ZBook G2 Jarod Wilson
2015-05-16 14:37 ` Bjorn Helgaas
2015-05-16 14:41 ` Bjorn Helgaas
2015-05-18 0:26 ` Rafael J. Wysocki
2015-05-18 14:33 ` Jarod Wilson
2015-05-18 16:17 ` Jarod Wilson
2015-05-18 20:45 ` Jarod Wilson
2015-05-18 23:06 ` Rafael J. Wysocki
2015-05-19 3:06 ` Jarod Wilson
2015-05-19 11:36 ` Rafael J. Wysocki
2015-05-19 11:43 ` [PATCH] PCIe / hotplug: Drop pointless ACPI-based "slot detection" check Rafael J. Wysocki
2015-05-19 12:42 ` Jarod Wilson
2015-05-19 13:29 ` Rafael J. Wysocki
2015-05-19 13:27 ` [Update][PATCH] " Rafael J. Wysocki
2015-05-19 14:40 ` Jarod Wilson [this message]
2015-05-21 16:11 ` Bjorn Helgaas
2015-05-22 1:21 ` Rafael J. Wysocki
2015-06-11 17:05 ` Jarod Wilson
2015-06-11 20:38 ` Jarod Wilson
2015-06-11 21:16 ` Rafael J. Wysocki
2015-06-11 21:49 ` Jarod Wilson
2015-05-18 21:57 ` [PATCH] pci/hotplug: work-around for missing _RMV on HP ZBook G2 Rafael J. Wysocki
2015-05-18 14:30 ` Jarod Wilson
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