From: Jesse Barnes Subject: Re: [PATCH] PCI / PM: Do not use native PCIe PME by default Date: Fri, 18 Jun 2010 09:37:01 -0700 Message-ID: <20100618093701.681dc238@virtuousgeek.org> References: <201006181704.22550.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <201006181704.22550.rjw@sisk.pl> Sender: linux-pci-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Len Brown , ACPI Devel Maling List , Matthew Garrett , linux-pm@lists.linux-foundation.org, Andrew Morton , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org List-Id: linux-acpi@vger.kernel.org On Fri, 18 Jun 2010 17:04:22 +0200 "Rafael J. Wysocki" wrote: > From: Rafael J. Wysocki >=20 > 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 Kamen=C3=ADk and > others, is that the ACPI GPE associated with PCIe hotplug keeps > firing continuously causing kacpid to take substantial percentage > of CPU time. >=20 > 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=3D command line switch. >=20 > Fixes https://bugzilla.kernel.org/show_bug.cgi?id=3D15924 , which is > a listed regression from 2.6.33. >=20 > Signed-off-by: Rafael J. Wysocki > Reported-by: Jaroslav Kamen=C3=ADk > Tested-by: Antoni Grzymala =20 > --- Applied to my for-linus tree, thanks. --=20 Jesse Barnes, Intel Open Source Technology Center