Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752592AbcL2Lxn (ORCPT ); Thu, 29 Dec 2016 06:53:43 -0500 Received: from smtprelay.synopsys.com ([198.182.47.9]:35349 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751358AbcL2Lxm (ORCPT ); Thu, 29 Dec 2016 06:53:42 -0500 Subject: Re: [PATCH] pci: rename *host* directory to *controller* To: Kishon Vijay Abraham I , Joao Pinto , Bjorn Helgaas References: <1482912577-31356-1-git-send-email-kishon@ti.com> <20161228092228.GA14025@infradead.org> <20161228164118.GB19653@bhelgaas-glaptop.roam.corp.google.com> <1ee66ce2-c321-2341-c964-c8b32218ca7e@synopsys.com> <426f0cb8-b9d4-7c0d-5eea-0ae0d4b01668@synopsys.com> <5864A335.9000203@ti.com> <5864F812.5050605@ti.com> CC: Christoph Hellwig , Bjorn Helgaas , , , , Linus Torvalds From: Joao Pinto Message-ID: <1d5f9c4b-b619-36fc-082c-962c34cc3194@synopsys.com> Date: Thu, 29 Dec 2016 11:53:36 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <5864F812.5050605@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.107.19.116] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5104 Lines: 129 ?s 11:48 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: > Hi, > > On Thursday 29 December 2016 04:08 PM, Joao Pinto wrote: >> >> Hi, >> >> ?s 5:46 AM de 12/29/2016, Kishon Vijay Abraham I escreveu: >>> Hi, >>> >>> On Wednesday 28 December 2016 10:50 PM, Joao Pinto wrote: >>>> ?s 5:17 PM de 12/28/2016, Joao Pinto escreveu: >>>>> ?s 4:41 PM de 12/28/2016, Bjorn Helgaas escreveu: >>>>>> On Wed, Dec 28, 2016 at 01:57:13PM +0000, Joao Pinto wrote: >>>>>>> ?s 9:22 AM de 12/28/2016, Christoph Hellwig escreveu: >>>>>>>> On Wed, Dec 28, 2016 at 01:39:37PM +0530, Kishon Vijay Abraham I wrote: >>>>>>>>> As discussed during our LPC discussions, I'm posting the rename patch >>>>>>>>> here. I'll post the rest of EP series before the next merge window. >>>>>>>>> >>>>>>>>> There might be hiccups because of this renaming but feel this is >>>>>>>>> necessary for long-term maintenance. >>>>>>>> >>>>>>>> if we do this rename it would be great to get it to Linus NOW after >>>>>>>> -rc1 as that minimizes the impact on the 4.11 merge window. >>>>>>> >>>>>>> Rename it to controller is a bit vague I thing since we have the PCI Endpoint IP >>>>>>> also. Wouldn't be better to name it rc_controller? >>>>>> >>>>>> I think Kishon's whole goal is to add PCI Endpoint IP, so he wants a >>>>>> neutral name that can cover both RC and Endpoint. >>> >>> right. >>>>>> >>>>>> I'm not a huge fan of "controller" because it feels a little bit long >>>>>> and while I suppose it technically does include the concept of the PCI >>>>>> interface of an endpoint, it still suggests more of the host side to >>>>>> me. >>>>>> >>>>>> Doesn't USB have a similar situation? I see there's a >>>>>> drivers/usb/host/ (probably where we copied from in the first place). >>>>>> Is a USB gadget the USB analog of what you're doing? How do they >>>>>> share code between the master/slave sides? >>>>>> >>>>> >>>>> The usb/host contains the implemnentations by the spec of the several >>>>> *hci (USB Host) and then you can have for example the USB 3.0 Designware >>>>> Host specific ops in dwc3 and for USB 2.0 in dwc2/. >>> >>> right, each IP have a separate directory in USB. I thought of doing something >>> similar for PCI but decided against it since that would involve identifying all >>> the PCI IPs used and eventually result in more directories. >>>>> For device purposes it uses the core/ and then some of the device functions >>>>> are extended from the gadget/ package in which you can use mass_storage and >>>>> other types of functions. >>> >>> That would be similar for PCI endpoint. All endpoint specific core >>> functionality will be added in drivers/pci/endpoint (see RFC [1]). >>>>> >>>>> In our case in PCI we have the core functions inside /drivers/pci and the host >>>>> mangled inside host. I suggest: >>>>> >>>>> drivers/pci >>>>> drivers/pci/core/ >>>>> drivers/pci/core/hotplug >>>>> drivers/pci/core/pcie >>>>> drivers/pci/core/ >>>>> drivers/pci/host >>>>> drivers/pci/dwc -> here would be pcie-designware and the specific vendor drivers >>>> >>>> Correction: >>>> drivers/pci/host/dwc -> here would be pcie-designware and the specific vendor >>>> drivers >>>> >>>>> drivers/pci/ -> here would be the drivers for vendorN controller >>>> >>>> Correction: >>>> drivers/pci/host/ -> here would be the drivers for vendorN controller >>>> >>>>> drivers/pci/endpoint -> common code >>>>> drivers/pci/endpoint/dwc -> implementation of Synopsys specific endpoint ops >>>>> drivers/pci/ -> implementation of other vendors specific endpoint ops >>> >>> There are some parts of the dwc driver that is common to both root complex and >>> endpoint. Where should that be? I'm sure no one wants to duplicate the common >>> piece in both root complex and endpoint. >> >> You are right, the config space is almost the same and some ops also common. >> I would suggest: >> >> drivers/pci >> drivers/pci/core/ >> drivers/pci/core/hotplug >> drivers/pci/core/pcie >> drivers/pci/core/ >> drivers/pci/dwc >> drivers/pci/dwc/common.c -> common ops and registers between RC and endpoint >> drivers/pci/dwc/host/ >> drivers/pci/dwc/endpoint/ >> >> What do you think? > > I don't think we should have sub-directories within dwc (USB too doesn't have > sub-directories). Where should the platform specific driver be kept? For > example pci-dra7xx.c (which use dwc) has both rc and ep specific parts but the > changes are so minimal that splitting the file won't make much sense. > > And such a change would also mean we create a separate directory for every > other driver present right now in pci/host. I understand you idea. We can simplify it this way: drivers/pci drivers/pci/core/ drivers/pci/core/hotplug drivers/pci/core/pcie drivers/pci/core/ drivers/pci/dwc -> Common files (RC and EP), specific vendor drivers for EP and EP BTW dwc states for DesigWare Controller. What do you think? Thanks > > Thanks > Kishon >