Hey there, this question arose during some discussion with someone concerning the Exynos mixer and G2D. The question is the following. Consider the Exynos mixer when run under the IOMMU (that's sysmmu_tv IIRC). What exactly does setup the IOMMU mapping so that the mixer can scanout the framebuffer? There is exynos_gem_map_sgt_with_dma() in the Exynos GEM code, but it's currently exclusively used for the G2D and only when dealing with userptr (and not GEM) there. I was looking at exynos_drm_alloc_buf() since this called when allocating a BO to be used as scanout. I see dma_alloc_attrs() being called, which also sets the DMA address that is later used in the mixer code. But DMA_ATTR_NO_KERNEL_MAPPING is passed, so no mapping is done at this point. Is the mapping done somewhere else, or is it simply not necessary here? With best wishes, Tobias -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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