Hi John,

On Wed, Nov 14, 2018 at 01:04:25AM +0800, John Garry wrote:
> The following linker failure can be seen for a certain heavily reduced
> defconfig:
> drivers/soc/sunxi/sunxi_sram.o: In function `sunxi_sram_probe':
> drivers/soc/sunxi/sunxi_sram.c:353: undefined reference to `__devm_regmap_init_mmio_clk'
> drivers/soc/sunxi/sunxi_sram.c:353:(.text+0x3c4): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `__devm_regmap_init_mmio_clk'
> 
> It would seem that the sunxi sram driver implicitly depended on config
> REGMAP_MMIO.
> 
> To solve, select config REGMAP_MMIO for ARCH_SUNXI. This seems a better
> option than selecting from the respective driver config as this just
> defaults to ARCH_SUNXI.
> 
> Fixes: 5828729bebbb ("soc: sunxi: export a regmap for EMAC clock reg on A64")
> Signed-off-by: John Garry <john.garry@huawei.com>
> 
> diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> index 51bc479..c8a6ad3 100644
> --- a/arch/arm64/Kconfig.platforms
> +++ b/arch/arm64/Kconfig.platforms
> @@ -12,6 +12,7 @@ config ARCH_SUNXI
>  	select ARCH_HAS_RESET_CONTROLLER
>  	select GENERIC_IRQ_CHIP
>  	select PINCTRL
> +	select REGMAP_MMIO
>  	select RESET_CONTROLLER
>  	help
>  	  This enables support for Allwinner sunxi based SoCs like the A64.

The sunxi_sram driver has a Kconfig symbol of its own now, it would
make more sense to add that select there, especially since we can also
compile it for arm.

Maxime

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com