From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:40990 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752405AbcA2XGs (ORCPT ); Fri, 29 Jan 2016 18:06:48 -0500 Date: Fri, 29 Jan 2016 17:06:45 -0600 From: Bjorn Helgaas To: Sinan Kaya Cc: Lorenzo Pieralisi , linux-pci@vger.kernel.org, Zhou Wang , Phil Edworthy , Bjorn Helgaas Subject: Re: [RFC] ARM/ARM64 PCI_PROBE_ONLY platforms Message-ID: <20160129230645.GG12965@localhost> References: <20160120160427.GD13437@red-moon> <569FB210.9090605@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <569FB210.9090605@codeaurora.org> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Jan 20, 2016 at 11:13:04AM -0500, Sinan Kaya wrote: > On 1/20/2016 11:04 AM, Lorenzo Pieralisi wrote: > > > > We want to get rid of PCI_PROBE_ONLY on ARM/ARM64: > > For platforms that does not have UEFI BIOS, it makes sense to remove the probe only > option as the firmware is not doing anything. I don't understand this statement. It sounds like you mean "non-UEFI BIOS firmware doesn't assign PCI BARs", but that's not true, so you must mean something else. > For server like arm64 platforms, the behavior should be identical to > x86 world. > The UEFI BIOS sets up the resources, kernel uses the resources. Is there actually a requirement that a UEFI BIOS assign resources to PCI BARs? I know that historically, x86 BIOS has set up most or all PCI BARs. But I thought there was something in UEFI that relaxed that, so it would only have to program BARs for the boot and console devices it actually needed. But I can't find a spec reference either way. Bjorn