From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiang Liu Subject: Re: [PATCH v2 1/7] ACPI: Add CONFIG_HOTPLUG_OST option Date: Fri, 11 May 2012 08:15:26 +0800 Message-ID: <4FAC5A1E.3090602@gmail.com> References: <1336507944-10219-1-git-send-email-toshi.kani@hp.com> <1336507944-10219-2-git-send-email-toshi.kani@hp.com> <4FABEF90.4040602@gmail.com> <1336670790.16730.215.camel@misato.fc.hp.com> <4FABFE33.9040502@gmail.com> <1336674019.16730.239.camel@misato.fc.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pz0-f46.google.com ([209.85.210.46]:40501 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706Ab2EKAPd (ORCPT ); Thu, 10 May 2012 20:15:33 -0400 In-Reply-To: <1336674019.16730.239.camel@misato.fc.hp.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Toshi Kani Cc: lenb@kernel.org, linux-acpi@vger.kernel.org, bhelgaas@google.com, shuahkhan@gmail.com, linux-kernel@vger.kernel.org On 05/11/2012 02:20 AM, Toshi Kani wrote: > On Fri, 2012-05-11 at 01:43 +0800, Jiang Liu wrote: >> On 05/11/2012 01:26 AM, Toshi Kani wrote: >>> On Fri, 2012-05-11 at 00:40 +0800, Jiang Liu wrote: >>>> On 05/09/2012 04:12 AM, Toshi Kani wrote: >>>>> Added CONFIG_ACPI_HOTPLUG_OPT option. When this config option is disabled, >>>>> this patchset has no effect on the platform. This option is disabled by >>>>> default. The dependency list assures consistent behavior among CPU, memory >>>>> and container hotplug operations with regarding the _OST support. >>>> Seems also need to enhance the acpiphp driver for PCI hotplug operations too. >>>> acpiphp driver is also based on the ACPI device hotplug model. >>> >>> Good question. ACPI PCI hotplug is a legacy method, which is being >>> replaced by PCI native hotplug. I expect PCI native hotplug will be >>> used for any platforms supporting PCI-E. Since this _OST support is >>> targeted for new platforms (as _OST is not supported on the current >>> platforms), I thought that it would be prudent to avoid changing PCI >>> hotplug code for this. >> You are right, acpiphp is legacy method. But it may also be used to support >> some cases which can't be supported by the pciehp driver. >> For example, we have a PCIe system which needs to run acpiphp and pciehp >> concurrently. The pciehp driver is used to manage hot-pluggable PCIe slot, >> and the acpiphp driver is used to migrate downstream ports among virtual >> PCIe switches of an MR-IOV switch. It would be great if we could enable >> _OST for acpiphp too. >> >> To be honest, our BIOS doesn't provide _OST for acpiphp yet, so we could >> enhance acpiphp driver in future when a system really needing that feature >> appears. > > Interesting. In such case, I am willing to change acpiphp, but I am > afraid that I do not have access to platforms with ACPI PCI hotplug > support. My test systems are all PCI-E based. So, it would be great if > you could enhance acpiphp when you need it. Sure, I will enhance it based on your work when needed. Thanks! -Gerry > > > Thanks! > -Toshi >