Hi "Enrico,

I love your patch! Yet something to improve:

[auto build test ERROR on gpio/for-next]
[also build test ERROR on linux/master linus/master v5.10-rc7 next-20201207]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Enrico-Weigelt-metux-IT-consult/drivers-gpio-add-virtio-gpio-guest-driver/20201208-045646
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for-next
config: i386-randconfig-m021-20201207 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/fff1ac3789d850604f11c95b185116bea68e26a9
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Enrico-Weigelt-metux-IT-consult/drivers-gpio-add-virtio-gpio-guest-driver/20201208-045646
        git checkout fff1ac3789d850604f11c95b185116bea68e26a9
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/Kconfig:74:error: recursive dependency detected!
   drivers/gpu/drm/Kconfig:74: symbol DRM_KMS_HELPER is selected by DRM_VIRTIO_GPU
   drivers/gpu/drm/virtio/Kconfig:2: symbol DRM_VIRTIO_GPU depends on VIRTIO
   drivers/virtio/Kconfig:2: symbol VIRTIO is selected by GPIO_VIRTIO
   drivers/gpio/Kconfig:1628: symbol GPIO_VIRTIO depends on GPIOLIB
   drivers/gpio/Kconfig:14: symbol GPIOLIB is selected by I2C_MUX_LTC4306
   drivers/i2c/muxes/Kconfig:47: symbol I2C_MUX_LTC4306 depends on I2C
   drivers/i2c/Kconfig:8: symbol I2C is selected by FB_DDC
   drivers/video/fbdev/Kconfig:63: symbol FB_DDC depends on FB
   drivers/video/fbdev/Kconfig:12: symbol FB is selected by DRM_KMS_FB_HELPER
   drivers/gpu/drm/Kconfig:80: symbol DRM_KMS_FB_HELPER depends on DRM_KMS_HELPER
   For a resolution refer to Documentation/kbuild/kconfig-language.rst
   subsection "Kconfig recursive dependency limitations"

vim +74 drivers/gpu/drm/Kconfig

6fcefd56f5060c Dave Airlie   2009-09-08 @74  config DRM_KMS_HELPER
13a8195b148615 Dave Airlie   2009-09-07  75  	tristate
13a8195b148615 Dave Airlie   2009-09-07  76  	depends on DRM
92b6f89f6b85f4 Daniel Vetter 2013-10-08  77  	help
92b6f89f6b85f4 Daniel Vetter 2013-10-08  78  	  CRTC helpers for KMS drivers.
92b6f89f6b85f4 Daniel Vetter 2013-10-08  79  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org