On 11/05/16 21:11, Arnd Bergmann wrote: > We get a harmless build warning when trying to use the mediatek > DRM driver with IOMMU support disabled: > > warning: (DRM_MEDIATEK) selects IOMMU_DMA which has unmet direct dependencies > (IOMMU_SUPPORT) > > However, the IOMMU_DMA symbol is not meant to be used by drivers > at all, and this driver doesn't seem to have a strict dependency > on it other than using the mediatek IOMMU driver that does. > > Since we also want to be able to do compile tests with the > driver on other platforms, the IOMMU_DMA symbol should not > be selected here. > > Signed-off-by: Arnd Bergmann <arnd at arndb.de> > --- > If someone has a better explanation about why the 'select' is here, > let me know, it certainly seems out of place.
Ack - it's neither an IOMMU driver nor a DMA API implementation, so it has no business with IOMMU_DMA. If there's an IOMMU dependency in general it should be on MTK_IOMMU, not underlying implementation details. Robin. > drivers/gpu/drm/mediatek/Kconfig | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/Kconfig > b/drivers/gpu/drm/mediatek/Kconfig > index 0c06a69d7f04..545973f6b743 100644 > --- a/drivers/gpu/drm/mediatek/Kconfig > +++ b/drivers/gpu/drm/mediatek/Kconfig > @@ -7,7 +7,6 @@ config DRM_MEDIATEK > select DRM_KMS_HELPER > select DRM_MIPI_DSI > select DRM_PANEL > - select IOMMU_DMA > select MEMORY > select MTK_SMI > help >
