From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C11A4C43387 for ; Mon, 17 Dec 2018 14:55:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A591206A2 for ; Mon, 17 Dec 2018 14:55:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733243AbeLQOzB convert rfc822-to-8bit (ORCPT ); Mon, 17 Dec 2018 09:55:01 -0500 Received: from mail.bootlin.com ([62.4.15.54]:57682 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727258AbeLQOzB (ORCPT ); Mon, 17 Dec 2018 09:55:01 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id B0A5A20510; Mon, 17 Dec 2018 15:54:58 +0100 (CET) Received: from xps13 (aaubervilliers-681-1-89-7.w90-88.abo.wanadoo.fr [90.88.30.7]) by mail.bootlin.com (Postfix) with ESMTPSA id 5509120CDF; Mon, 17 Dec 2018 15:54:26 +0100 (CET) Date: Mon, 17 Dec 2018 15:54:26 +0100 From: Miquel Raynal To: "Rafael J. Wysocki" 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 Subject: Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support Message-ID: <20181217155426.71058a03@xps13> In-Reply-To: <61805564.abKDZ2rVK7@aspire.rjw.lan> References: <20181123141831.8214-1-miquel.raynal@bootlin.com> <20181213105302.GA5330@e107981-ln.cambridge.arm.com> <20181213153000.245d7d5f@xps13> <61805564.abKDZ2rVK7@aspire.rjw.lan> Organization: Bootlin X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Rafael, "Rafael J. Wysocki" wrote on Thu, 13 Dec 2018 22:50:51 +0100: > 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? Absolutely, yes :) I am actively working on it in parallel, you can check the third version there [1]. Stephen Boyd has a slightly different idea of how it should be done, I will propose a v4 this week, I can add you in copy if you are interested! Anyway, there is one thing that is still missing: * Let's have device A that requests clock B * With the device link series, A is linked (as a child) to B. * A suspend/resume hooks handle things in the NOIRQ phase. * B suspend/resume hooks handle things in the default phase. What I expected during a suspend: 1/ ->suspend_noirq(device A) 2/ ->suspend(clock B) Unfortunately, device links do not seem to enforce any priority between phases (default/late/noirq) and what happens is: 1/ ->suspend(B) 2/ ->suspend_noirq(A) Which has no sense in my case. Hence, I had to request the clock suspend/resume callbacks to be upgraded to the NOIRQ phase as well (I don't have a better solution for now). This is still under discussion in a thread you have been recently added to by Bjorn, see [2]. So when I told you I was not confident in "reworking the PM core to respect such dependency", this is what I was referring to. I am definitely ready to help, but I don't feel I can do it alone. [1] https://www.spinics.net/lists/linux-clk/msg32824.html [2] https://marc.info/?l=linux-pm&m=154465198510735&w=2 Thanks, Miquèl From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2B72C43387 for ; Mon, 17 Dec 2018 14:55:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 72550206A2 for ; Mon, 17 Dec 2018 14:55:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="pw9Jv/9K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72550206A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ta6KO57mncCbRXrgaOZ4jN5ZcMMgwEQZNnziKLnYIIM=; b=pw9Jv/9K5rWy0z MP2hWZJzaYHn9B9jYqk03zVapnGpXIyxpKcgPeOkHiRbhjWCOgRpPOek26NGt+doxGt5neCx6CHEi I35ptIn0gyAEj0eQQ5PYVIbRzGdLYncbc5mjZMt5aR2RiwIbBqxOA4hy7CwQhPZFFbTdUlMGQWyae kdaMWITW1BXTXnXee1YSJq6JCiyvkC3mJ3PTlcckeALnEvY6ziYseDH+GaD58uPQYqsh2ONUBNS8V wQ3taWdUkuvLDGapq1RGC2ZUQg43EK0wRrUcSUPuiRHTffQbDaoiZZpWE5ZDM+U0pjVRx33QMtW5X 1mrxYqOafH0NZb2c4gyg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gYuIc-00051t-38; Mon, 17 Dec 2018 14:55:14 +0000 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gYuIY-0003lR-9I for linux-arm-kernel@lists.infradead.org; Mon, 17 Dec 2018 14:55:12 +0000 Received: by mail.bootlin.com (Postfix, from userid 110) id B0A5A20510; Mon, 17 Dec 2018 15:54:58 +0100 (CET) Received: from xps13 (aaubervilliers-681-1-89-7.w90-88.abo.wanadoo.fr [90.88.30.7]) by mail.bootlin.com (Postfix) with ESMTPSA id 5509120CDF; Mon, 17 Dec 2018 15:54:26 +0100 (CET) Date: Mon, 17 Dec 2018 15:54:26 +0100 From: Miquel Raynal To: "Rafael J. Wysocki" Subject: Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support Message-ID: <20181217155426.71058a03@xps13> In-Reply-To: <61805564.abKDZ2rVK7@aspire.rjw.lan> References: <20181123141831.8214-1-miquel.raynal@bootlin.com> <20181213105302.GA5330@e107981-ln.cambridge.arm.com> <20181213153000.245d7d5f@xps13> <61805564.abKDZ2rVK7@aspire.rjw.lan> Organization: Bootlin X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181217_065510_600974_5ED7AB7B X-CRM114-Status: GOOD ( 21.46 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Andrew Lunn , Lorenzo Pieralisi , Jason Cooper , devicetree@vger.kernel.org, Stephen Boyd , linux-pci@vger.kernel.org, Gregory Clement , linux-kernel@vger.kernel.org, Maxime Chevallier , Nadav Haklai , Antoine Tenart , Rob Herring , Thomas Petazzoni , sudeep.holla@arm.com, Bjorn Helgaas , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org SGkgUmFmYWVsLAoKIlJhZmFlbCBKLiBXeXNvY2tpIiA8cmp3QHJqd3lzb2NraS5uZXQ+IHdyb3Rl IG9uIFRodSwgMTMgRGVjIDIwMTgKMjI6NTA6NTEgKzAxMDA6Cgo+IE9uIFRodXJzZGF5LCBEZWNl bWJlciAxMywgMjAxOCAzOjMwOjAwIFBNIENFVCBNaXF1ZWwgUmF5bmFsIHdyb3RlOgo+ID4gSGkg TG9yZW56bywKPiA+ICAgCj4gPiA+ID4gSWYgdGhhdCdzIHJlYWxseSB0aGUgY2FzZSwgdGhlbiBJ IGNhbiBzZWUgaG93IG9uZSBkZXZpY2UgYW5kIGl0J3MKPiA+ID4gPiBjaGlsZHJlbiBhcmUgc3Vz cGVuZGVkIGFuZCB0aGUgaXJxIGZvciBpdCBpcyBkaXNhYmxlZCBidXQgdGhlIHByb3ZpZGluZwo+ ID4gPiA+IGRldmljZXMgKGNsaywgcmVndWxhdG9yLCBidXMgY29udHJvbGxlciwgZXRjLikgYXJl IHN0aWxsIGZ1bGx5IGFjdGl2ZQo+ID4gPiA+IGFuZCBub3Qgc3VzcGVuZGVkIGJ1dCBpbiBmYWN0 IGNvbXBsZXRlbHkgdXNhYmxlIGFuZCBhYmxlIHRvIHNlcnZpY2UKPiA+ID4gPiBpbnRlcnJ1cHRz LiBJZiB0aGF0IGFsbCBtYWtlcyBzZW5zZSwgdGhlbiBJIHdvdWxkIGFuc3dlciB0aGUgcXVlc3Rp b24KPiA+ID4gPiB3aXRoIGEgZGVmaW5pdGl2ZSAieWVzIGl0J3MgYWxsIGZpbmUiIGJlY2F1c2Ug dGhlIGNsayBjb25zdW1lciBjb3VsZCBiZQo+ID4gPiA+IGluIHRoZSBOT0lSUSBwaGFzZSBvZiBp dHMgc3VzcGVuZCBidXQgdGhlIGNsayBwcm92aWRlciB3b3VsZG4ndCBoYXZlCj4gPiA+ID4gZXZl biBzdGFydGVkIHN1c3BlbmRpbmcgeWV0IHdoZW4gY2xrX2Rpc2FibGVfdW5wcmVwYXJlKCkgaXMg Y2FsbGVkLiAgICAKPiA+ID4gCj4gPiA+IFRoYXQncyBhIHZlcnkgZ29vZCBzdW1tYXJ5IGFuZCBh ZGRyZXNzIG15IGNvbmNlcm4sIEkgc3RpbGwgcXVlc3Rpb24gdGhpcwo+ID4gPiBwYXRjaCBjb3Jy ZWN0bmVzcyAoYW5kIG1hbnkgb3RoZXJzIHRoYXQgY2Fycnkgb3V0IGNsayBvcGVyYXRpb25zIGlu IFMyUgo+ID4gPiBOT0lSUSBwaGFzZSksIHRoZXkgbWF5IHdvcmsgYnV0IGRvIG5vdCB0ZWxsIG1l IHRoZXkgYXJlIHJvY2sgc29saWQgZ2l2ZW4KPiA+ID4geW91ciBhY2N1cmF0ZSBzdW1tYXJ5IGFi b3ZlLiAgCj4gPiAKPiA+IEkgdW5kZXJzdGFuZCB5b3VyIGNvbmNlcm4gYnV0IEkgZG9uJ3Qgc2Vl IGFueSBhbHRlcm5hdGl2ZSByaWdodCBub3cKPiA+IGFuZCBhIGRlZXAgcmV3b3JrIG9mIHRoZSBQ TSBjb3JlIHRvIHJlc3BlY3Qgc3VjaCBkZXBlbmRlbmN5IGlzIG5vdAo+ID4gc29tZXRoaW5nIHRo YXQgY2FuIGJlIGRvbmUgaW4gYSByZWFzb25hYmxlIGFtb3VudCBvZiB0aW1lLiAgCj4gCj4gTWF5 YmUgeW91IGRvbid0IG5lZWQgdG8gcmV3b3JrIGFueXRoaW5nLiA6LSkKPiAKPiBIYXZlIHlvdSBj b25zaWRlcmVkIHVzaW5nIGRldmljZSBsaW5rcz8KCkFic29sdXRlbHksIHllcyA6KSBJIGFtIGFj dGl2ZWx5IHdvcmtpbmcgb24gaXQgaW4gcGFyYWxsZWwsIHlvdSBjYW4KY2hlY2sgdGhlIHRoaXJk IHZlcnNpb24gdGhlcmUgWzFdLiBTdGVwaGVuIEJveWQgaGFzIGEgc2xpZ2h0bHkKZGlmZmVyZW50 IGlkZWEgb2YgaG93IGl0IHNob3VsZCBiZSBkb25lLCBJIHdpbGwgcHJvcG9zZSBhIHY0IHRoaXMg d2VlaywKSSBjYW4gYWRkIHlvdSBpbiBjb3B5IGlmIHlvdSBhcmUgaW50ZXJlc3RlZCEKCkFueXdh eSwgdGhlcmUgaXMgb25lIHRoaW5nIHRoYXQgaXMgc3RpbGwgbWlzc2luZzoKKiBMZXQncyBoYXZl IGRldmljZSBBIHRoYXQgcmVxdWVzdHMgY2xvY2sgQgoqIFdpdGggdGhlIGRldmljZSBsaW5rIHNl cmllcywgQSBpcyBsaW5rZWQgKGFzIGEgY2hpbGQpIHRvIEIuCiogQSBzdXNwZW5kL3Jlc3VtZSBo b29rcyBoYW5kbGUgdGhpbmdzIGluIHRoZSBOT0lSUSBwaGFzZS4KKiBCIHN1c3BlbmQvcmVzdW1l IGhvb2tzIGhhbmRsZSB0aGluZ3MgaW4gdGhlIGRlZmF1bHQgcGhhc2UuCgpXaGF0IEkgZXhwZWN0 ZWQgZHVyaW5nIGEgc3VzcGVuZDoKMS8gLT5zdXNwZW5kX25vaXJxKGRldmljZSBBKQoyLyAtPnN1 c3BlbmQoY2xvY2sgQikKClVuZm9ydHVuYXRlbHksIGRldmljZSBsaW5rcyBkbyBub3Qgc2VlbSB0 byBlbmZvcmNlIGFueSBwcmlvcml0eSBiZXR3ZWVuCnBoYXNlcyAoZGVmYXVsdC9sYXRlL25vaXJx KSBhbmQgd2hhdCBoYXBwZW5zIGlzOgoxLyAtPnN1c3BlbmQoQikKMi8gLT5zdXNwZW5kX25vaXJx KEEpCldoaWNoIGhhcyBubyBzZW5zZSBpbiBteSBjYXNlLiBIZW5jZSwgSSBoYWQgdG8gcmVxdWVz dCB0aGUgY2xvY2sKc3VzcGVuZC9yZXN1bWUgY2FsbGJhY2tzIHRvIGJlIHVwZ3JhZGVkIHRvIHRo ZSBOT0lSUSBwaGFzZSBhcyB3ZWxsIChJCmRvbid0IGhhdmUgYSBiZXR0ZXIgc29sdXRpb24gZm9y IG5vdykuIFRoaXMgaXMgc3RpbGwgdW5kZXIgZGlzY3Vzc2lvbgppbiBhIHRocmVhZCB5b3UgaGF2 ZSBiZWVuIHJlY2VudGx5IGFkZGVkIHRvIGJ5IEJqb3JuLCBzZWUgWzJdLgoKU28gd2hlbiBJIHRv bGQgeW91IEkgd2FzIG5vdCBjb25maWRlbnQgaW4gInJld29ya2luZyB0aGUgUE0gY29yZSB0bwpy ZXNwZWN0IHN1Y2ggZGVwZW5kZW5jeSIsIHRoaXMgaXMgd2hhdCBJIHdhcyByZWZlcnJpbmcgdG8u IEkgYW0KZGVmaW5pdGVseSByZWFkeSB0byBoZWxwLCBidXQgSSBkb24ndCBmZWVsIEkgY2FuIGRv IGl0IGFsb25lLgoKWzFdIGh0dHBzOi8vd3d3LnNwaW5pY3MubmV0L2xpc3RzL2xpbnV4LWNsay9t c2czMjgyNC5odG1sClsyXSBodHRwczovL21hcmMuaW5mby8/bD1saW51eC1wbSZtPTE1NDQ2NTE5 ODUxMDczNSZ3PTIKCgpUaGFua3MsCk1pcXXDqGwKCl9fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4 LWFybS1rZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9y Zy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK