Re: linux-next: build warning after merge of the regmap tree

From: Mark Brown
Date: Mon Nov 06 2017 - 06:21:54 EST


On Mon, Nov 06, 2017 at 03:30:37PM +1100, Stephen Rothwell wrote:
> On Mon, 6 Nov 2017 15:21:57 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> > On Mon, 6 Nov 2017 11:52:14 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> > > After merging the regmap tree, today's linux-next build
> > > (arm_multi_v7_defconfig) produced this warning:

Not snipping Kconfig errors for context, looks like Kconfig is exploding...

> > > drivers/gpio/Kconfig:13:error: recursive dependency detected!
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/gpio/Kconfig:13: symbol GPIOLIB is selected by PINCTRL_SUNXI
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/pinctrl/sunxi/Kconfig:3: symbol PINCTRL_SUNXI is selected by PINCTRL_SUN6I_A31_R
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/pinctrl/sunxi/Kconfig:21: symbol PINCTRL_SUN6I_A31_R depends on RESET_CONTROLLER
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/reset/Kconfig:4: symbol RESET_CONTROLLER is selected by QCOM_SCM
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/firmware/Kconfig:205: symbol QCOM_SCM is selected by QCOM_ADSP_PIL
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/remoteproc/Kconfig:90: symbol QCOM_ADSP_PIL depends on QCOM_SMEM
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/soc/qcom/Kconfig:49: symbol QCOM_SMEM depends on HWSPINLOCK
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/hwspinlock/Kconfig:5: symbol HWSPINLOCK is selected by REGMAP
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/base/regmap/Kconfig:6: symbol REGMAP is selected by PINCTRL_SX150X
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/pinctrl/Kconfig:227: symbol PINCTRL_SX150X is selected by GPIO_SX150X
> > > For a resolution refer to Documentation/kbuild/kconfig-language.txt
> > > subsection "Kconfig recursive dependency limitations"
> > > drivers/gpio/Kconfig:821: symbol GPIO_SX150X depends on GPIOLIB
> > > warning: (ARCH_VEXPRESS) selects MFD_VEXPRESS_SYSREG which has unmet direct dependencies (HAS_IOMEM && VEXPRESS_CONFIG && GPIOLIB && !ARCH_USES_GETTIMEOFFSET)
> > > warning: (ARCH_NOMADIK && ARCH_U8500) selects PINCTRL_NOMADIK which has unmet direct dependencies (PINCTRL && (ARCH_U8500 || ARCH_NOMADIK) && OF && GPIOLIB)
> > > warning: (PINCTRL_AT91 && PINCTRL_AT91PIO4 && PINCTRL_MESON && PINCTRL_OXNAS && PINCTRL_PISTACHIO && PINCTRL_PIC32 && PINCTRL_NOMADIK && PINCTRL_MTK && GPIO_TB10X) selects OF_GPIO which has unmet direct dependencies (GPIOLIB && OF && HAS_IOMEM)

> > > Maybe introduced by commit

> > > f25637a6b89e ("regmap: Add a config option for hwspinlock")

> > Things got worse during the day until config started segfaulting, so I
> > reverted this commit.

> That necessitated me reverting commits

> 8698b9364710 ("regmap: Add hardware spinlock support")
> 267f3e4f18f1 ("regmap: Also protect hwspinlock in error handling path")
> e8419c40a5ad ("regmap: Clean up hwspinlock on regmap exit")

This seems like there's a Kconfig bug, it's claiming HWSPINLOCK is
selected by regmap but the select is conditional and not actually
enabled. You could potentially get a recursive dependency but there
isn't one right now. The root issue here is that HWSPINLOCK can be
built modular which makes it very painful to use from core code.

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