On Wed, 01 Apr 2015, Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > After adding virtio-gpu I get this funky kconfig dependency loop. > > scripts/kconfig/conf --oldconfig Kconfig > drivers/video/fbdev/Kconfig:5:error: recursive dependency detected! > drivers/video/fbdev/Kconfig:5: symbol FB is selected by DRM_KMS_FB_HELPER > drivers/gpu/drm/Kconfig:34: symbol DRM_KMS_FB_HELPER is selected by DRM_VIRTIO_GPU > drivers/gpu/drm/virtio/Kconfig:1: symbol DRM_VIRTIO_GPU depends on VIRTIO > drivers/virtio/Kconfig:1: symbol VIRTIO is selected by REMOTEPROC > drivers/remoteproc/Kconfig:4: symbol REMOTEPROC is selected by OMAP_REMOTEPROC > drivers/remoteproc/Kconfig:12: symbol OMAP_REMOTEPROC depends on OMAP_IOMMU > drivers/iommu/Kconfig:141: symbol OMAP_IOMMU is selected by VIDEO_OMAP3 > drivers/media/platform/Kconfig:96: symbol VIDEO_OMAP3 depends on VIDEO_V4L2 > drivers/media/v4l2-core/Kconfig:6: symbol VIDEO_V4L2 depends on I2C > drivers/i2c/Kconfig:7: symbol I2C is selected by FB_DDC > drivers/video/fbdev/Kconfig:59: symbol FB_DDC is selected by FB_CYBER2000_DDC > drivers/video/fbdev/Kconfig:374: symbol FB_CYBER2000_DDC depends on FB_CYBER2000 > drivers/video/fbdev/Kconfig:362: symbol FB_CYBER2000 depends on FB > > Making VIDEO_OMAP3 depend on OMAP_IOMMU instead of selecting it breaks the > loop, which looks like the best way to handle it to me. I'm open to better > suggestions though. I think part of the problem is that "select" is often used not as documented [1] but rather as "show my config in menuconfig for convenience even if my dependency is not met, and select the dependency even though I know it can screw up the dependency chain". In light of the documentation, your patch seems to DTRT. (Disclaimer: I don't work with the drivers in question, hence no Reviewed-by.) In the big picture, it feels like menuconfig needs a way to display items whose dependencies are not met, and a way to recursively enable said items and all their dependencies when told. This would reduce the resistance to sticking with "select" when clearly "depends" is what's meant. BR, Jani. [1] Documentation/kbuild/kconfig-language.txt: "In general use select only for non-visible symbols (no prompts anywhere) and for symbols with no dependencies. That will limit the usefulness but on the other hand avoid the illegal configurations all over." > > Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> > --- > drivers/media/platform/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig > index d9b872b..fc21734 100644 > --- a/drivers/media/platform/Kconfig > +++ b/drivers/media/platform/Kconfig > @@ -87,8 +87,8 @@ config VIDEO_OMAP3 > tristate "OMAP 3 Camera support" > depends on VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API && ARCH_OMAP3 > depends on HAS_DMA > + depends on OMAP_IOMMU > select ARM_DMA_USE_IOMMU > - select OMAP_IOMMU > select VIDEOBUF2_DMA_CONTIG > ---help--- > Driver for an OMAP 3 camera controller. > -- > 1.8.3.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
