On Mon, Feb 29, 2016 at 01:13:31PM +0100, Arnd Bergmann wrote:

CONFIG_DMI is a user-selectable Kconfig symbol that some drivers
depend on. As part of a recent patch, other drivers started
adding a 'select' for the same symbol, which now causes
a recursive dependency:

drivers/gpio/Kconfig:34:error: recursive dependency detected!
subsection "Kconfig recursive dependency limitations"
drivers/gpio/Kconfig:34:        symbol GPIOLIB is selected by GEOS
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
arch/x86/Kconfig:2591:  symbol GEOS depends on DMI
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
arch/x86/Kconfig:815:   symbol DMI is selected by DELL_LAPTOP
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/platform/x86/Kconfig:104:       symbol DELL_LAPTOP depends on BACKLIGHT_CLASS_DEVICE
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/video/backlight/Kconfig:158:    symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/video/fbdev/Kconfig:192:        symbol FB_BACKLIGHT is selected by FB_SSD1307
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/video/fbdev/Kconfig:2462:       symbol FB_SSD1307 depends on GPIOLIB

Basically we should either always use 'depends on' or always use 'select'
to avoid this kind of loop. Using 'depends on' is more useful here,
as it still allows users to turn off the symbol of they really
want to, without having to track down every driver selecting it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: cbd9d95b2b27 ("dell-wmi, dell-laptop: select DMI")

Thanks Arnd, queued to testing.

-- 
Darren Hart
Intel Open Source Technology Center