From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Message-ID: <62140.117.114.135.40.1466678343.squirrel@mprc.pku.edu.cn> In-Reply-To: <20160622230746.GI25485@localhost> References: <1465383890-13538-1-git-send-email-lorenzo.pieralisi@arm.com> <1465383890-13538-5-git-send-email-lorenzo.pieralisi@arm.com> <20160622230746.GI25485@localhost> Date: Thu, 23 Jun 2016 18:39:03 +0800 (CST) Subject: Re: [PATCH v3 4/4] ARM/PCI: remove arch specific pcibios_enable_device() From: "Xuetao Guan" To: "Bjorn Helgaas" MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: gxt@mprc.pku.edu.cn Cc: Lorenzo Pieralisi , Russell King , Arnd Bergmann , David Daney , linux-pci@vger.kernel.org, Will Deacon , Catalin Marinas , Bjorn Helgaas , Guan Xuetao , Yinghai Lu , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: > [+cc Guan] > > On Wed, Jun 08, 2016 at 12:04:50PM +0100, Lorenzo Pieralisi wrote: >> The arm pcibios_enable_device() implementation exists solely >> to prevent enabling PCI resources on PCI_PROBE_ONLY systems, since >> on those systems the PCI resources are currently not claimed (ie >> inserted in the PCI resource tree - which means their parent >> pointer is not correctly set-up) therefore they can not be enabled >> since this would trigger PCI set-ups failures. >> >> After removing the pci=firmware command line option in: >> >> commit 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware >> command line parameter handling") > > 903589ca7165 removed "pci=firmware" from ARM and from > Documentation/kernel-parameters.txt (where it was documented as > ARM-specific). > > I think unicore32 copied that code from arm, so unicore32 is one of > the few remaining arches that can set PCI_PROBE_ONLY. I suspect this > was just copied from arm and may not be necessary on unicore32. > > Guan, can you confirm that PCI_PROBE_ONLY is necessary on unicore32, > or that it can be removed? > Yes, this code was copied from arm, and it's not necessary. It can be removed safely. Guan Xuetao _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: gxt@mprc.pku.edu.cn (Xuetao Guan) Date: Thu, 23 Jun 2016 18:39:03 +0800 (CST) Subject: [PATCH v3 4/4] ARM/PCI: remove arch specific pcibios_enable_device() In-Reply-To: <20160622230746.GI25485@localhost> References: <1465383890-13538-1-git-send-email-lorenzo.pieralisi@arm.com> <1465383890-13538-5-git-send-email-lorenzo.pieralisi@arm.com> <20160622230746.GI25485@localhost> Message-ID: <62140.117.114.135.40.1466678343.squirrel@mprc.pku.edu.cn> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > [+cc Guan] > > On Wed, Jun 08, 2016 at 12:04:50PM +0100, Lorenzo Pieralisi wrote: >> The arm pcibios_enable_device() implementation exists solely >> to prevent enabling PCI resources on PCI_PROBE_ONLY systems, since >> on those systems the PCI resources are currently not claimed (ie >> inserted in the PCI resource tree - which means their parent >> pointer is not correctly set-up) therefore they can not be enabled >> since this would trigger PCI set-ups failures. >> >> After removing the pci=firmware command line option in: >> >> commit 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware >> command line parameter handling") > > 903589ca7165 removed "pci=firmware" from ARM and from > Documentation/kernel-parameters.txt (where it was documented as > ARM-specific). > > I think unicore32 copied that code from arm, so unicore32 is one of > the few remaining arches that can set PCI_PROBE_ONLY. I suspect this > was just copied from arm and may not be necessary on unicore32. > > Guan, can you confirm that PCI_PROBE_ONLY is necessary on unicore32, > or that it can be removed? > Yes, this code was copied from arm, and it's not necessary. It can be removed safely. Guan Xuetao