From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RFC PATCH] PCIe: Add PCIe runtime D3cold support Date: Wed, 18 Apr 2012 21:52:51 +0200 Message-ID: <201204182152.51421.rjw@sisk.pl> References: <4F8790F6.5080408@intel.com> <201204172243.39525.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: huang ying Cc: "Yan, Zheng" , bhelgaas@google.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Lin Ming , Zhang Rui , ACPI Devel Mailing List List-Id: linux-acpi@vger.kernel.org On Wednesday, April 18, 2012, huang ying wrote: > On Wed, Apr 18, 2012 at 4:43 AM, Rafael J. Wysocki wrote: > > On Tuesday, April 17, 2012, huang ying wrote: > >> On Tue, Apr 17, 2012 at 10:12 AM, Yan, Zheng wrote: > >> > On 04/17/2012 01:07 AM, Rafael J. Wysocki wrote: > >> > > >> >> BTW, can you please explain to me what the #WAKE signal is and how it is > >> >> different from PME#? > >> > > >> > #WAKE signal is triggered by a pin connected to the root complex or other > >> > motherboard logic. PME# is triggered by PME message sent to the port. > >> > >> PME# is a PCI pin, while WAKE# is a PCI Express pin. In PCI Express, > >> there is no PME#, PME is delivered between end point device and root > >> port or root complex event collector via PME message, and the PME > >> message will trigger IRQ on root port or root complex event collector. > >> WAKE# is not used for PCI Express D1, D2 and D3hot, it is just used > >> by D3cold. When remote wakeup detected by end point device, it will > >> assert WAKE# to notify power controller (implemented via ACPI on some > >> platform), then power controller will turn on power for main link, > >> after link goes back to L0, PME message will be sent to root port or > >> root complex event collector by end point device. > > > > OK > > > > So do I understand correctly that the WAKE# signal here is the one described > > in Section 5.3.3.2 Link Wakeup of PCI Express Base spec. 2.0? > > > > So what happens is that it triggers a GPE and that GPE has a _Lxx method > > associated with it, I suppose. Is that correct? > > Yes. So I wonder what that _Lxx method looks like. Thanks, Rafael