From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:42166 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755869AbeFOM6y (ORCPT ); Fri, 15 Jun 2018 08:58:54 -0400 Date: Fri, 15 Jun 2018 13:58:47 +0100 From: Lorenzo Pieralisi To: Guenter Roeck Cc: Rob Herring , Bjorn Helgaas , Scott Branden , linux-pci@vger.kernel.org, Jan Kiszka , Ley Foon Tan , Russell King Subject: Re: [v4] PCI: improve host drivers compile test coverage Message-ID: <20180615125847.GA7735@e107981-ln.cambridge.arm.com> References: <20180405193154.27897-1-robh@kernel.org> <20180612170229.GA10141@roeck-us.net> <20180613100935.GA7707@e107981-ln.cambridge.arm.com> <20180613181146.GA28856@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180613181146.GA28856@roeck-us.net> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Jun 13, 2018 at 11:11:46AM -0700, Guenter Roeck wrote: > On Wed, Jun 13, 2018 at 11:09:35AM +0100, Lorenzo Pieralisi wrote: > > [+Jan, Ley Foon, RMK] > > > > On Tue, Jun 12, 2018 at 10:02:29AM -0700, Guenter Roeck wrote: > > > On Thu, Apr 05, 2018 at 02:31:54PM -0500, Rob Herring wrote: > > > > Add COMPILE_TEST on driver config options with it. Some ARM drivers > > > > still have arch dependencies, so we have to keep those dependent on ARM. > > > > > > > > Cc: Lorenzo Pieralisi > > > > Cc: Bjorn Helgaas > > > > Cc: linux-pci@vger.kernel.org > > > > Signed-off-by: Rob Herring > > > > > > This patch has the undesirable side effect that it selects PCI_DOMAINS for > > > sparc32:allmodconfig, which in turn results in > > > > > > drivers/ata/pata_ali.c: In function 'ali_init_chipset': > > > drivers/ata/pata_ali.c:469:38: error: > > > implicit declaration of function 'pci_domain_nr'; did you mean 'pci_iomap_wc'? > > > > > > Unfortunately, 37bd62d224c82 ("PCI: Enable PCI_DOMAINS along with generic > > > PCI host controller") has pretty much the same result. No idea how to fix > > > the problem, so I won't even try. > > > > Sorry about that. > > > > One option would consist in removing all PCI_DOMAINS selection from > > drivers/pci/controller/Kconfig and delegate it to arches even though > > this would force PCI_DOMAINS selection on all ARM platforms (it is > > already selected for ARCH_MULTIPLATFORM). > > > > Or we add back arch dependency to the relevant host bridges. > > > > Everything else I have in mind seems overkill to me given that this > > patch was added to improve test coverage (we could add a default > > pci_domain_nr() stub - weak or #define - that returns 0 in case arches > > do not provide an implementation but do we really want to do that ?). > > > > Thoughts appreciated. > > > > From the definition of PCI_DOMAINS, I suspect the original idea was that > drivers should depend on it, not select it. Especially auto-selecting > it with PCI_HOST_GENERIC seems like a bad idea to me. However, that is > just me. I'll leave it up to Bjorn to decide what if anything he wants > to do about it. Here is a patch that should reinstate the previous behaviour but it will make PCI_DOMAINS a visible option on ARM 32-bit systems; whether that's acceptable that's the question I need to answer, it should honour old configs and it does not force PCI_DOMAINS selection on non-DT arch/arm PCI host controllers (that do not need PCI_DOMAINS anyway so I suspect that enabling it on all ARM 32-bit platforms should not break anything but I preferred to be cautious). If I hear no complaints I will post it for inclusion, we cannot leave things as they are. Lorenzo -- >8 -- diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2a78bdef9a24..1d415aeb54b4 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1244,8 +1244,14 @@ config PCI VESA. If you have PCI, say Y, otherwise N. config PCI_DOMAINS - bool + bool "Support for multiple PCI domains" depends on PCI + help + Enable PCI domains kernel management. Say Y if your machine + has a PCI bus hierarchy that requires more than one PCI + domain (aka segment) to be correctly managed. Say N otherwise. + + If you don't know what to do here, say N. config PCI_DOMAINS_GENERIC def_bool PCI_DOMAINS diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig index 18fa09b3ac8f..cc9fa02d32a0 100644 --- a/drivers/pci/controller/Kconfig +++ b/drivers/pci/controller/Kconfig @@ -96,7 +96,6 @@ config PCI_HOST_GENERIC depends on OF select PCI_HOST_COMMON select IRQ_DOMAIN - select PCI_DOMAINS help Say Y here if you want to support a simple generic PCI host controller, such as the one emulated by kvmtool. @@ -138,7 +137,6 @@ config PCI_VERSATILE config PCIE_IPROC tristate - select PCI_DOMAINS help This enables the iProc PCIe core controller support for Broadcom's iProc family of SoCs. An appropriate bus interface driver needs @@ -176,7 +174,6 @@ config PCIE_IPROC_MSI config PCIE_ALTERA bool "Altera PCIe controller" depends on ARM || NIOS2 || COMPILE_TEST - select PCI_DOMAINS help Say Y here if you want to enable PCIe controller support on Altera FPGA. -- 2.15.0