On Wed, Jan 23, 2019 at 09:45:56AM +0100, Lukas Wunner wrote:

On Tue, Jan 22, 2019 at 06:13:11AM -0800, Ronald Tschalär wrote:

quoted

commit d6abe6df706c66d803e6dd4fe98c1b6b7f125a56 (drm/bridge:
sil_sii8620: do not have a dependency of RC_CORE) added a dependency on
INPUT. However, this causes problems with other drivers, in particular
an input driver that depends on MFD_INTEL_LPSS_PCI (to be added in a
future commit):

  drivers/clk/Kconfig:9:error: recursive dependency detected!
  drivers/clk/Kconfig:9:        symbol COMMON_CLK is selected by MFD_INTEL_LPSS
  drivers/mfd/Kconfig:566:      symbol MFD_INTEL_LPSS is selected by MFD_INTEL_LPSS_PCI
  drivers/mfd/Kconfig:580:      symbol MFD_INTEL_LPSS_PCI is implied by KEYBOARD_APPLESPI
  drivers/input/keyboard/Kconfig:73:    symbol KEYBOARD_APPLESPI depends on INPUT
  drivers/input/Kconfig:8:      symbol INPUT is selected by DRM_SIL_SII8620
  drivers/gpu/drm/bridge/Kconfig:83:    symbol DRM_SIL_SII8620 depends on DRM_BRIDGE
  drivers/gpu/drm/bridge/Kconfig:1:     symbol DRM_BRIDGE is selected by DRM_PL111
  drivers/gpu/drm/pl111/Kconfig:1:      symbol DRM_PL111 depends on COMMON_CLK

According to the docs, select should only be used for non-visible
symbols. Furthermore almost all other references to INPUT throughout the
kernel config are depends, not selects. Hence this change.

I think this is not as cut and dry. We should be able to select needed
subsystems (such as INPUT, USB, etc) even if they are user visible.
User, when enabling a piece of hardware, does not need to know ultimate
details of all subsystems the driver might need ti function.

It looks like one of the drivers implies MFD_INTEL_LPSS_PCI, maybe
treating imply the same as select when detecting circular dependency is
wrong as we are allowed to deselect implied dependencies?

quoted

CC: Inki Dae <inki.dae@samsung.com>
CC: Andrzej Hajda <redacted>
Signed-off-by: Ronald Tschalär <redacted>

Reviewed-by: Lukas Wunner <lukas@wunner.de>

I think this needs to be merged through the input tree as a prerequisite
for the applespi.c driver (keyboard + touchpad driver for 2015+ MacBook,
MacBook Air and MacBook Pro which uses SPI instead of USB) to avoid
breaking the build.  Adding Dmitry.

I have no idea what applespi.c is (it is definitely not in my tree), so
I think it should be merged through the same tree that the original
commit was introduced through.

Thanks,

Lukas

quoted

---
 drivers/gpu/drm/bridge/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 2fee47b0d50b..eabedc83f25c 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig

@@ -83,9 +83,9 @@ config DRM_PARADE_PS8622
 config DRM_SIL_SII8620
 	tristate "Silicon Image SII8620 HDMI/MHL bridge"
 	depends on OF
+	depends on INPUT
 	select DRM_KMS_HELPER
 	imply EXTCON
-	select INPUT
 	select RC_CORE

Keeping "select RC_CORE" is wrong though, as the driver appears to be
working find without RC. Maybe it should be stubbed out?

Thanks.

-- 
Dmitry