From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tx2outboundpool.messaging.microsoft.com (tx2ehsobe004.messaging.microsoft.com [65.55.88.14]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "MSIT Machine Auth CA 2" (not verified)) by ozlabs.org (Postfix) with ESMTPS id D67012C00A3 for ; Tue, 29 Oct 2013 05:22:17 +1100 (EST) Message-ID: <1382984523.3410.23.camel@snotra.buserror.net> Subject: Re: [PATCH 02/12][v3] pci: fsl: add structure fsl_pci From: Scott Wood To: Lian Minghuan-b31939 Date: Mon, 28 Oct 2013 13:22:03 -0500 In-Reply-To: <526A086E.305@freescale.com> References: <1382524894-15164-1-git-send-email-Minghuan.Lian@freescale.com> <1382524894-15164-2-git-send-email-Minghuan.Lian@freescale.com> <2B28E421-9B64-4CEC-9E00-8893502CE12F@kernel.crashing.org> <526A086E.305@freescale.com> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Cc: Arnd Bergmann , linux-pci@vger.kernel.org, Minghuan Lian , Bjorn Helgaas , "linuxppc-dev@lists.ozlabs.org list" , linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2013-10-25 at 13:58 +0800, Lian Minghuan-b31939 wrote: > Hi Kumar, > > please see my comment inline. > > On 10/24/2013 12:11 PM, Kumar Gala wrote: > > On Oct 23, 2013, at 5:41 AM, Minghuan Lian wrote: > > > >> PowerPC uses structure pci_controller to describe PCI controller, > >> but ARM uses structure pci_sys_data. In order to support PowerPC > >> and ARM simultaneously, the patch adds a structure fsl_pci that > >> contains most of the members of the pci_controller and pci_sys_data. > >> Meanwhile, it defines a interface fsl_arch_sys_to_pci() which should > >> be implemented in architecture-specific PCI controller driver to > >> convert pci_controller or pci_sys_data to fsl_pci. > >> > >> Signed-off-by: Minghuan Lian > >> --- > >> change log: > >> v1-v3: > >> Derived from http://patchwork.ozlabs.org/patch/278965/ > >> > >> Based on upstream master. > >> Based on the discussion of RFC version here > >> http://patchwork.ozlabs.org/patch/274487/ > >> > >> include/linux/fsl/pci-common.h | 41 +++++++++++++++++++++++++++++++++++++++++ > >> 1 file changed, 41 insertions(+) > > NAK. > > > > We discussed this some at the ARM Summit this week and the feeling is we need to move to a common interface between the various ARCHs. > [Minghuan] Do you mean we will use the common interface instead of > arch/powerpc/kernel/pci-common.c... > and arch/arm/kernel/bios32.c? Who will do the code movement and when > will the work be completed? The patches just move the common functions > of FSL PCI controller operation which can be re-used by PowerPC and ARM. > LS1 is coming, I worry about not having enough time to wait for the move > is completed. I agree -- it can take quite a while to get from "the feeling is we need to move to a common interface" to actually having something we can use. If and when this unification is achieved, we can drop this extra layer. It's a better interim solution than just duplicating the entire driver and letting them drift apart. -Scott