From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756872AbdCXAso convert rfc822-to-8bit (ORCPT ); Thu, 23 Mar 2017 20:48:44 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:22151 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752476AbdCXAse (ORCPT ); Thu, 23 Mar 2017 20:48:34 -0400 From: Gabriele Paoloni To: Gabriele Paoloni , Arnd Bergmann , Yuanzhichang CC: Mark Rutland , Benjamin Herrenschmidt , Rafael Wysocki , linux-pci , Will Deacon , Linuxarm , Frank Rowand , "Lorenzo Pieralisi" , ACPI Devel Maling List , "linux-serial@vger.kernel.org" , Catalin Marinas , "devicetree@vger.kernel.org" , Corey Minyard , "liviu.dudau@arm.com" , Rob Herring , Bjorn Helgaas , "kantyzc@163.com" , "zhichang.yuan02@gmail.com" , Linux ARM , "Rafael J. Wysocki" , Linux Kernel Mailing List , Zou Rongrong Subject: RE: [PATCH V7 5/7] ACPI: Delay the enumeration on the devices whose dependency has not met Thread-Topic: [PATCH V7 5/7] ACPI: Delay the enumeration on the devices whose dependency has not met Thread-Index: AQHSpDTps6VwfdgDmEW1ICZqy/qk/g== Date: Fri, 24 Mar 2017 00:23:55 +0000 Message-ID: References: <1489372963-9000-1-git-send-email-yuanzhichang@hisilicon.com> <1489372963-9000-6-git-send-email-yuanzhichang@hisilicon.com> <4600523.rWNiWKrYZC@aspire.rjw.lan> <58C9F6C6.4090700@hisilicon.com> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.202.9.150] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090203.58D46732.007B,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=169.254.1.78, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 4f82e9a03cc08506c3a9413136a60b48 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd > -----Original Message----- > From: linuxarm-bounces@huawei.com [mailto:linuxarm-bounces@huawei.com] > On Behalf Of Gabriele Paoloni > Sent: 16 March 2017 16:14 > To: Arnd Bergmann; Yuanzhichang > Cc: Mark Rutland; Benjamin Herrenschmidt; Rafael Wysocki; linux-pci; > Will Deacon; Linuxarm; Frank Rowand; Lorenzo Pieralisi; ACPI Devel > Maling List; linux-serial@vger.kernel.org; Catalin Marinas; > devicetree@vger.kernel.org; Corey Minyard; liviu.dudau@arm.com; Rob > Herring; Bjorn Helgaas; kantyzc@163.com; zhichang.yuan02@gmail.com; > Linux ARM; Rafael J. Wysocki; Linux Kernel Mailing List; Zou Rongrong > Subject: RE: [PATCH V7 5/7] ACPI: Delay the enumeration on the devices > whose dependency has not met > > Hi Arnd > > > -----Original Message----- > > From: arndbergmann@gmail.com [mailto:arndbergmann@gmail.com] On > Behalf > > Of Arnd Bergmann > > Sent: 16 March 2017 10:13 > > To: Yuanzhichang > > Cc: Rafael J. Wysocki; Catalin Marinas; Will Deacon; Rob Herring; > Frank > > Rowand; Bjorn Helgaas; Rafael Wysocki; Mark Rutland; Linux ARM; ACPI > > Devel Maling List; Lorenzo Pieralisi; Benjamin Herrenschmidt; Linux > > Kernel Mailing List; Linuxarm; devicetree@vger.kernel.org; linux-pci; > > linux-serial@vger.kernel.org; Corey Minyard; liviu.dudau@arm.com; Zou > > Rongrong; John Garry; Gabriele Paoloni; zhichang.yuan02@gmail.com; > > kantyzc@163.com; xuwei (O) > > Subject: Re: [PATCH V7 5/7] ACPI: Delay the enumeration on the > devices > > whose dependency has not met > > > > On Thu, Mar 16, 2017 at 3:21 AM, zhichang.yuan > > wrote: > > > Hi, Rafael, > > > > > > Thanks for your review! > > > > > > On 2017/3/14 5:24, Rafael J. Wysocki wrote: > > >> On Monday, March 13, 2017 10:42:41 AM zhichang.yuan wrote: > > >>> In commit 40e7fcb1929(ACPI: Add _DEP support to fix battery issue > > on Asus > > >>> T100TA), the '_DEP' was supported to solve the dependency of Asus > > battery. But > > >>> this patch is specific to Asus battery device. > > >>> In the real world, there are other devices which need the > > dependency to play the > > >>> role on the enumeration order. For example, all the Hip06 LPC > > >>> periperals(IPMI-BT, uart, etc) must be scanned after the LPC host > > driver > > >>> finished the probing. So, it makes sense to add a checking > whether > > the ACPI > > >>> device meet all the dependencies during its enumeration slot, if > > not, the > > >>> enumeration will be delayed till all dependency master finish > their > > work. > > >>> > > >>> This patch adds the dependency checking in ACPI enumeration, also > > the > > >>> corresponding handling to retrigger the Hip06 LPC peripherals' > > scanning. > > >> > > >> AFAICS, _DEP is generally abused in the wild and cannot be made > > generic. Sorry. > > >> > > > > > > From the ACPI specification, _DEP is for operation region accesses. > > > You are right... > > > > > > How about we add a ACPI handler for our LPC bus?? Just like amba. > > > In this way, we also can solve the issue about LPC enumeration > order. > > > > As far as I can tell, PCI and LPC have exactly the same requirement > > here, > > so whatever you end up doing for one should be used for the other as > > well. > > Well as you know PCI has got his own handler, identified by his own > namespace id "PNP0A03". > Now when you say "you end up doing for one should be used for the > other" > are you saying that we should introduce a new class of devices? > i.e. should we have an ACPI namespace identifier for non-PCI IO Host > Controllers? > > Otherwise, if my understanding is correct, having a specific new ACPI > handler for HiSilicon LPC would mean to adding another function_init() > in the list of acpi handlers inits in acpi_scan_init(). > > But then every vendor would declare his own one...is this really > correct? Do you have any feedback on this? Otherwise I think that maybe we could consider moving back to the arch_initcall approach as proposed in V6: https://lkml.org/lkml/2017/1/24/28 Thanks Gab > > Many Thanks > Gab > > > > > Arnd > _______________________________________________ > linuxarm mailing list > linuxarm@huawei.com > http://rnd-openeuler.huawei.com/mailman/listinfo/linuxarm