From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <55AFA741.2010703@roeck-us.net> Date: Wed, 22 Jul 2015 07:22:57 -0700 From: Guenter Roeck MIME-Version: 1.0 To: Lorenzo Pieralisi , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" CC: Ralf Baechle , "James E.J. Bottomley" , Michael Ellerman , Bjorn Helgaas , Richard Henderson , Benjamin Herrenschmidt , David Howells , Russell King , Tony Luck , "David S. Miller" , Ingo Molnar , Michal Simek , Chris Zankel , Arnd Bergmann , Krzysztof Halasa , Phil Edworthy , Jason Gunthorpe , Jingoo Han , Lucas Stach , Simon Horman , Minghuan Lian , Murali Karicheri , Tanmay Inamdar , Kishon Vijay Abraham I , Thierry Reding , Thomas Petazzoni , Will Deacon , Jayachandran C , "suravee.suthikulpanit@amd.com" Subject: Re: [RFT PATCH v3] PCI: move pci_read_bridge_bases to the generic PCI layer References: <1436439557-21075-1-git-send-email-lorenzo.pieralisi@arm.com> <20150722091427.GB344@red-moon> In-Reply-To: <20150722091427.GB344@red-moon> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: On 07/22/2015 02:14 AM, Lorenzo Pieralisi wrote: > Bjorn, Guenter, > > On Thu, Jul 09, 2015 at 11:59:16AM +0100, Lorenzo Pieralisi wrote: >> When a PCI bus is scanned, upon PCI bridge detection the kernel >> has to read the bridge registers to set-up its resources so that >> the PCI resource hierarchy can be validated properly. >> >> Most if not all architectures read PCI bridge registers in the >> pcibios_fixup_bus hook, that is called by the PCI generic layer >> whenever a PCI bus is scanned. >> >> Since pci_read_bridge_bases is an arch agnostic operation (and it >> is carried out on all architectures) it can be moved to the generic >> PCI layer in order to consolidate code and remove the respective >> calls from the architectures back-ends. >> >> The PCI_PROBE_ONLY flag is not checked before calling >> pci_read_bridge_buses in the generic layer since reading the bridge >> bases is not related to resources assignment; this implies that it >> can be carried out safely on PCI_PROBE_ONLY systems too and should >> not affect architectures (alpha, mips) that check the PCI_PROBE_ONLY >> flag before reading the bridge bases. >> >> Signed-off-by: Lorenzo Pieralisi >> Cc: Ralf Baechle >> Cc: James E.J. Bottomley >> Cc: Michael Ellerman >> Cc: Bjorn Helgaas >> Cc: Richard Henderson >> Cc: Benjamin Herrenschmidt >> Cc: David Howells >> Cc: Russell King >> Cc: Tony Luck >> Cc: David S. Miller >> Cc: Ingo Molnar >> Cc: Guenter Roeck >> Cc: Michal Simek >> Cc: Chris Zankel >> --- >> v2->v3: >> >> - Dropped RFC status >> - Removed bridge resources claiming from pci_read_bridge_bases() > > What do you want me to do with this patch ? I removed the resource > claiming - ie the only controversial bit, I can only test on > arm64, I would like to make some progress on this otherwise > I will have to add the bridge bases read to arm64 pcibios_fixup_bus() > and be done with this. > Lorenzo, please give me a few days to test it. I was out on vacation for the last two weeks, and I am still struggling to get my test systems back to a working state. Thanks, Guenter