From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF53DC43460 for ; Tue, 4 May 2021 14:24:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1EB461139 for ; Tue, 4 May 2021 14:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231576AbhEDOZB (ORCPT ); Tue, 4 May 2021 10:25:01 -0400 Received: from foss.arm.com ([217.140.110.172]:59244 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231580AbhEDOZB (ORCPT ); Tue, 4 May 2021 10:25:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EF76AED1; Tue, 4 May 2021 07:24:05 -0700 (PDT) Received: from lpieralisi (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4EF513F718; Tue, 4 May 2021 07:24:03 -0700 (PDT) Date: Tue, 4 May 2021 15:23:58 +0100 From: Lorenzo Pieralisi To: Bjorn Helgaas Cc: Greentime Hu , paul.walmsley@sifive.com, hes@sifive.com, erik.danie@sifive.com, zong.li@sifive.com, bhelgaas@google.com, robh+dt@kernel.org, aou@eecs.berkeley.edu, mturquette@baylibre.com, sboyd@kernel.org, p.zabel@pengutronix.de, alex.dewar90@gmail.com, khilman@baylibre.com, hayashi.kunihiko@socionext.com, vidyas@nvidia.com, jh80.chung@samsung.com, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org Subject: Re: [PATCH v6 5/6] PCI: fu740: Add SiFive FU740 PCIe host controller driver Message-ID: <20210504142358.GA25477@lpieralisi> References: <20210504105940.100004-6-greentime.hu@sifive.com> <20210504134632.GA1088165@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210504134632.GA1088165@bjorn-Precision-5520> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, May 04, 2021 at 08:46:32AM -0500, Bjorn Helgaas wrote: > On Tue, May 04, 2021 at 06:59:39PM +0800, Greentime Hu wrote: > > From: Paul Walmsley > > > > Add driver for the SiFive FU740 PCIe host controller. > > This controller is based on the DesignWare PCIe core. > > > > Signed-off-by: Paul Walmsley > > Co-developed-by: Henry Styles > > Signed-off-by: Henry Styles > > Co-developed-by: Erik Danie > > Signed-off-by: Erik Danie > > Co-developed-by: Greentime Hu > > Signed-off-by: Greentime Hu > > --- > > drivers/pci/controller/dwc/Kconfig | 10 + > > drivers/pci/controller/dwc/Makefile | 1 + > > drivers/pci/controller/dwc/pcie-fu740.c | 309 ++++++++++++++++++++++++ > > 3 files changed, 320 insertions(+) > > create mode 100644 drivers/pci/controller/dwc/pcie-fu740.c > > > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > > index 22c5529e9a65..255d43b1661b 100644 > > --- a/drivers/pci/controller/dwc/Kconfig > > +++ b/drivers/pci/controller/dwc/Kconfig > > @@ -318,4 +318,14 @@ config PCIE_AL > > required only for DT-based platforms. ACPI platforms with the > > Annapurna Labs PCIe controller don't need to enable this. > > > > +config PCIE_FU740 > > + bool "SiFive FU740 PCIe host controller" > > + depends on PCI_MSI_IRQ_DOMAIN > > + depends on SOC_SIFIVE || COMPILE_TEST > > + depends on GPIOLIB > > 1) I'm a little disappointed that I reported the build issue 6 days > ago when we were already in the merge window, and it's taken until > now to make some progress. > > 2) I would prefer not to depend on GPIOLIB because it reduces > compile-test coverage. For example, the x86_64 defconfig does not > enable GPIOLIB, so one must manually enable it to even be able to > enable PCIE_FU740. > > Many other PCI controller drivers use GPIO, but no others depend on > GPIOLIB, so I infer that in the !GPIOLIB case, gpio/consumer.h > provides the stubs required for compile testing. > > We could have a conversation about whether it's better to > explicitly depend on GPIOLIB here, or whether building a working > FU740 driver implicitly depends on GPIOLIB being selected > elsewhere. That implicit dependency *is* a little obscure, but I > think that's what other drivers currently do, and I'd like to do > this consistently unless there's a good reason otherwise. I will drop the explicit GPIOLIB dependency and push it out. For (1) I agree with you - I merged when I received some input - it is reasonable to avoid adding it to v5.13 material for this reason, apologies. Thanks, Lorenzo > Here are some examples of other drivers: > > dwc/pci-dra7xx.c: > config PCI_DRA7XX_HOST > depends on SOC_DRA7XX || COMPILE_TEST > > config SOC_DRA7XX > select ARCH_OMAP2PLUS > > config ARCH_OMAP2PLUS > select GPIOLIB > > dwc/pci-meson.c: > config PCI_MESON > # doesn't, but probably *should* depend on "ARCH_MESON || COMPILE_TEST" > > menuconfig ARCH_MESON > select GPIOLIB > > dwc/pcie-qcom.c: > config PCIE_QCOM > depends on OF && (ARCH_QCOM || COMPILE_TEST) > > config ARCH_QCOM > select GPIOLIB > > pcie-rockchip.c: > config PCIE_ROCKCHIP_HOST > depends on ARCH_ROCKCHIP || COMPILE_TEST > > config ARCH_ROCKCHIP > select GPIOLIB > > > + select PCIE_DW_HOST > > + help > > + Say Y here if you want PCIe controller support for the SiFive > > + FU740. > > + > > endmenu