Re: [PATCH] drm: bridge: fix unmet dependency on DRM_KMS_HELPER for DRM_PANEL_BRIDGE

[Julian Braha <julianbraha@gmail.com>]

On Monday, October 25, 2021 1:47:35 PM EDT you wrote:
> Hi Julian,
> 
> Thank you for the patch.
> 
> On Mon, Oct 25, 2021 at 01:42:02PM -0400, Julian Braha wrote:
> > When DRM_CHIPONE_ICN6211 is selected, and DRM_KMS_HELPER is not selected,
> > Kbuild gives the following warning:
> > 
> > WARNING: unmet direct dependencies detected for DRM_PANEL_BRIDGE
> >   Depends on [n]: HAS_IOMEM [=y] && DRM_BRIDGE [=y] && DRM_KMS_HELPER [=n]
> >   Selected by [y]:
> >   - DRM_CHIPONE_ICN6211 [=y] && HAS_IOMEM [=y] && DRM [=y] && DRM_BRIDGE [=y] && OF [=y]
> > 
> > This is because DRM_CHIPONE_ICN6211 selects DRM_PANEL_BRIDGE
> > without depending on or selecting DRM_KMS_HELPER,
> > despite DRM_PANEL_BRIDGE depending on DRM_KMS_HELPER.
> > 
> > This unmet dependency bug was detected by Kismet,
> > a static analysis tool for Kconfig.
> > Please advise if this is not the appropriate solution.
> 
> Shouldn't DRM_PANEL_BRIDGE select DRM_KMS_HELPER instead of depending on
> it ?
> 
> > Fixes: ce517f18944e ("drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge")
> > Reviewed-by: Robert Foss <robert.foss@linaro.org>
> > Signed-off-by: Julian Braha <julianbraha@gmail.com>
> > ---
> >  drivers/gpu/drm/bridge/Kconfig | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > index 431b6e12a81f..a630cb8fd1c8 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -30,6 +30,7 @@ config DRM_CDNS_DSI
> >  config DRM_CHIPONE_ICN6211
> >  	tristate "Chipone ICN6211 MIPI-DSI/RGB Converter bridge"
> >  	depends on OF
> > +  select DRM_KMS_HELPER
> >  	select DRM_MIPI_DSI
> >  	select DRM_PANEL_BRIDGE
> >  	help
> 
> 

Hi Laurent,

Either a "select" or a "depends" will resolve this issue, but
most similar devices in this Kconfig file select DRM_KMS_HELPER.
Is there something different about DRM_CHIPONE_ICN6211 that I have missed?

- Julian Braha