Re: [PATCH] ARM: ixp4xx: fix building both pci drivers

From: Linus Walleij <linus.walleij@linaro.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: "Linus Walleij" <linusw@kernel.org>, "SoC Team" <soc@kernel.org>,
	"Arnd Bergmann" <arnd@arndb.de>, "Imre Kaloz" <kaloz@openwrt.org>,
	"Krzysztof Halasa" <khalasa@piap.pl>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Linux ARM" <linux-arm-kernel@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>
Subject: Re: [PATCH] ARM: ixp4xx: fix building both pci drivers
Date: Wed, 21 Jul 2021 22:24:06 +0200	[thread overview]
Message-ID: <CACRpkdbuXkvOkMNizqmRPwuYz-YU8j-yidtXsOAmEd4z3B0hVA@mail.gmail.com> (raw)
In-Reply-To: <20210721151546.2325937-1-arnd@kernel.org>

On Wed, Jul 21, 2021 at 5:15 PM Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
>
> When both the old and the new PCI drivers are enabled
> in the same kernel, there are a couple of namespace
> conflicts that cause a build failure:
>
> drivers/pci/controller/pci-ixp4xx.c:38: error: "IXP4XX_PCI_CSR" redefined [-Werror]
>    38 | #define IXP4XX_PCI_CSR                  0x1c
>       |
> In file included from arch/arm/mach-ixp4xx/include/mach/hardware.h:23,
>                  from arch/arm/mach-ixp4xx/include/mach/io.h:15,
>                  from arch/arm/include/asm/io.h:198,
>                  from include/linux/io.h:13,
>                  from drivers/pci/controller/pci-ixp4xx.c:20:
> arch/arm/mach-ixp4xx/include/mach/ixp4xx-regs.h:221: note: this is the location of the previous definition
>   221 | #define IXP4XX_PCI_CSR(x) ((volatile u32 *)(IXP4XX_PCI_CFG_BASE_VIRT+(x)))
>       |
> drivers/pci/controller/pci-ixp4xx.c:148:12: error: 'ixp4xx_pci_read' redeclared as different kind of symbol
>   148 | static int ixp4xx_pci_read(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 *data)
>       |            ^~~~~~~~~~~~~~~
>
> Rename both the ixp4xx_pci_read/ixp4xx_pci_write functions and the
> IXP4XX_PCI_CSR macro. In each case, I went with the version that
> has fewer callers to keep the change small.
>
> Fixes: f7821b493458 ("PCI: ixp4xx: Add a new driver for IXP4xx")
> Cc: soc@kernel.org
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

I tried very hard to make it impossible to build both drivers at the
same time :(

Oh well I guess I failed. Kconfig ... say no more.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij