From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 6 Dec 2017 16:29:56 -0800 From: Brian Norris To: Tony Lindgren Cc: "Rafael J. Wysocki" , Jeffy Chen , linux-kernel@vger.kernel.org, bhelgaas@google.com, linux-pm@vger.kernel.org, shawn.lin@rock-chips.com, dianders@chromium.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, Len Brown Subject: Re: [RFC PATCH v10 6/7] PCI / PM: Move acpi wakeup code to pci core Message-ID: <20171207002955.GA40447@google.com> References: <20171027072612.26565-1-jeffy.chen@rock-chips.com> <1894178.xtK0vD2N4H@aspire.rjw.lan> <20171114025109.GA43048@google.com> <1882670.s3LR2t44nD@aspire.rjw.lan> <20171206193421.GA143886@google.com> <20171207001754.GB28152@atomide.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20171207001754.GB28152@atomide.com> Sender: linux-acpi-owner@vger.kernel.org List-ID: On Wed, Dec 06, 2017 at 04:17:54PM -0800, Tony Lindgren wrote: > * Brian Norris [171206 19:36]: > > By the way, it seems pretty ambiguous how we want to handle things like > > (a) multiple devices sharing the same WAKE# > > (b) systems where a slot is swappable > > > > For (a), the main problem is that if we have to repeat the interrupt > > definition in multiple devices, then we have to deal with something like > > IRQF_SHARED. That can be done, but it makes it much harder to use the > > dedicated wakeirq helpers. > > This will get messy, let's not go there :) That is unless the hardware > really has a single interrupt wired to multiple devices. And in that > case almost certainly a custom interrupt handler is needed. As Rafael mentioned, the spec doesn't clearly delineate a required hierarchy to the WAKE# pin, and it's certainly possible to share it. I'm fine dodging that question for now, and only writing said custom interrupt handler if/when needed. But device tree bindings are "forever", so it seems reasonable to at least agree how it should be defined. Brian