From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support Date: Thu, 13 Dec 2018 22:50:51 +0100 Message-ID: <61805564.abKDZ2rVK7@aspire.rjw.lan> References: <20181123141831.8214-1-miquel.raynal@bootlin.com> <20181213105302.GA5330@e107981-ln.cambridge.arm.com> <20181213153000.245d7d5f@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20181213153000.245d7d5f@xps13> Sender: linux-kernel-owner@vger.kernel.org To: Miquel Raynal Cc: Lorenzo Pieralisi , Stephen Boyd , sudeep.holla@arm.com, Gregory Clement , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Thomas Petazzoni , Bjorn Helgaas , devicetree@vger.kernel.org, Rob Herring , Mark Rutland , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Antoine Tenart , Maxime Chevallier , Nadav Haklai List-Id: devicetree@vger.kernel.org On Thursday, December 13, 2018 3:30:00 PM CET Miquel Raynal wrote: > Hi Lorenzo, > > > > If that's really the case, then I can see how one device and it's > > > children are suspended and the irq for it is disabled but the providing > > > devices (clk, regulator, bus controller, etc.) are still fully active > > > and not suspended but in fact completely usable and able to service > > > interrupts. If that all makes sense, then I would answer the question > > > with a definitive "yes it's all fine" because the clk consumer could be > > > in the NOIRQ phase of its suspend but the clk provider wouldn't have > > > even started suspending yet when clk_disable_unprepare() is called. > > > > That's a very good summary and address my concern, I still question this > > patch correctness (and many others that carry out clk operations in S2R > > NOIRQ phase), they may work but do not tell me they are rock solid given > > your accurate summary above. > > I understand your concern but I don't see any alternative right now > and a deep rework of the PM core to respect such dependency is not > something that can be done in a reasonable amount of time. Maybe you don't need to rework anything. :-) Have you considered using device links? Thanks, Rafael