Re: [PATCH 2/2] PCI: Drop controller CONFIG_OF dependencies

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	"Bjorn Helgaas" <bhelgaas@google.com>
Subject: Re: [PATCH 2/2] PCI: Drop controller CONFIG_OF dependencies
Date: Tue, 15 Nov 2022 16:56:10 +0100	[thread overview]
Message-ID: <CAMuHMdVnJZGqwnC0fZTwyb1GT5Nu+4K9LND4CXU96cvYG+qEgg@mail.gmail.com> (raw)
In-Reply-To: <20221025191339.667614-3-helgaas@kernel.org>

Hi Bjorn,

On Tue, Oct 25, 2022 at 9:16 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Many drivers depend on OF interfaces, so they won't be functional if
> CONFIG_OF is not set.  But OF provides stub functions in that case, so drop
> the OF dependencies so we can at least compile-test the drivers.
>
> This means we can compile-test the following drivers even without CONFIG_OF
> enabled (many still require either CONFIG_COMPILE_TEST or the relevant
> arch):
>
>   aardvark
>   al
>   apple
>   brcmstb
>   cadence-host
>   cadence-platform-host
>   cadence-ep
>   dra7xx-host
>   dra7xx-ep
>   dw-rockchip
>   ftpci100
>   hisi
>   intel-gw
>   ixp4xx
>   j721e-host
>   j721e-ep
>   kirin
>   layerscape-host
>   layerscape-ep
>   mediatek
>   microchip-host
>   mobiveil
>   mvebu
>   qcom-host
>   qcom-ep
>   rockchip-host
>   rockchip-ep
>   rockchip-dwc
>   pci-host-generic
>   uniphier-host
>   uniphier-ep
>   v3-semi
>   xilinx
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Thanks for your patch, which is now commit 51dfb612ab3becf9 ("PCI: Drop
controller CONFIG_OF dependencies") in pci/next.

> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -8,7 +8,6 @@ config PCI_MVEBU
>         depends on ARCH_MVEBU || ARCH_DOVE || COMPILE_TEST
>         depends on MVEBU_MBUS
>         depends on ARM
> -       depends on OF

This is exactly why we have the COMPILE_TEST symbol.
There is no point in bothering all users who configure kernels with
questions about drivers that won't function anyway due to missing
dependencies, unless the user explicitly wants to do compile-testing.

So all of these should become:

    depends on OF || COMPILE_TEST

>         select PCI_BRIDGE_EMUL
>         help
>          Add support for Marvell EBU PCIe controller. This PCIe controller

> @@ -98,7 +94,6 @@ config PCI_HOST_GENERIC
>
>  config PCIE_XILINX
>         bool "Xilinx AXI PCIe host bridge support"
> -       depends on OF || COMPILE_TEST

This one was fine.

>         depends on PCI_MSI_IRQ_DOMAIN
>         help
>           Say 'Y' here if you want kernel to support the Xilinx AXI PCIe

Thanks in advance for reverting or fixing!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds