From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <537FBF4F.4050406@amd.com> Date: Fri, 23 May 2014 16:36:15 -0500 From: Suravee Suthikulanit MIME-Version: 1.0 To: Robert Richter , Bjorn Helgaas CC: Borislav Petkov , Daniel J Blueman , Andreas Herrmann , "linux-kernel@vger.kernel.org" , "Aravind Gopalakrishnan" , "linux-pci@vger.kernel.org" , Borislav Petkov , Myron Stowe Subject: Re: [PATCH V5 3/4] x86/PCI: Stop enabling ECS for AMD CPUs after Fam16h References: <20140521231615.26447.38060.stgit@bhelgaas-glaptop.roam.corp.google.com> <20140521231817.26447.55150.stgit@bhelgaas-glaptop.roam.corp.google.com> <20140521233802.GA21575@pd.tnic> <20140522191746.GL4383@pd.tnic> <537E8ACF.6000103@amd.com> <20140523115622.GU27560@rric.localhost> In-Reply-To: <20140523115622.GU27560@rric.localhost> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: On 5/23/2014 6:56 AM, Robert Richter wrote: > On 22.05.14 20:54:54, Bjorn Helgaas wrote: >> I'm going to go out on a limb and guess that Windows does not enable >> ECS, so it probably uses ECAM. Therefore, I suspect Linux's parsing >> of MCFG is broken in some way, and we probably *could* use ECAM in all >> these cases I'm seeing. > > Even if ECS is not enabled the system should be fine anyway, as ECS is > only used to enable certain features. For family 10h this was > originally the IBS EILVT (extended interrupt local vector table, > needed for hw profiling) setup which need to be set by the OS which > the BIOS didn't right. This should be fixed now and properly set by > the BIOS on 15h+ systems. > > I don't remember what was added to 16h where ECS was needed, I think > there was one (Suravee?). Not sure if this is essential. I am not aware of anything specific in the family16h which require IO_ECS to be enabled. Suravee