Re: [PATCH] PCI / PM: Do not use native PCIe PME by default

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Fri, 18 Jun 2010 17:04:22 +0200
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Commit c7f486567c1d0acd2e4166c47069835b9f75e77b
> (PCI PM: PCIe PME root port service driver) causes the native PCIe
> PME signaling to be used by default, if the BIOS allows the kernel to
> control the standard configuration registers of PCIe root ports.
> However, the native PCIe PME is coupled to the native PCIe hotplug
> and calling pcie_pme_acpi_setup() makes some BIOSes expect that
> the native PCIe hotplug will be used as well.  That, in turn, causes
> problems to appear on systems where the PCIe hotplug driver is not
> loaded.  The usual symptom, as reported by Jaroslav Kameník and
> others, is that the ACPI GPE associated with PCIe hotplug keeps
> firing continuously causing kacpid to take substantial percentage
> of CPU time.
> 
> To work around this issue, change the default so that the native
> PCIe PME signaling is only used if directly requested with the help
> of the pcie_pme= command line switch.
> 
> Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15924 , which is
> a listed regression from 2.6.33.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> Reported-by: Jaroslav Kameník <jaroslav@kamenik.cz>
> Tested-by: Antoni Grzymala <antekgrzymala@gmail.com> 
> ---

Applied to my for-linus tree, thanks.

-- 
Jesse Barnes, Intel Open Source Technology Center