Hi Eizan and Hans, On 24/6/20 16:05, Hans Verkuil wrote: > On 06/05/2020 10:40, Eizan Miyamoto wrote: >> >> This series depends on all changes in the series: >> https://patchwork.kernel.org/patch/11530275/ > > I plan on merging the v3 of this series. > >> >> We are adding a dummy MDP component driver so that all the components >> are properly configured with IOMMUs and LARBs. This is required for >> us to get hardware video decode working in 4.19, and possibly newer >> kernels. > > What is the status of this series? > First of all, sorry, I should have had answer before but for some reason I missed the track of this patchset. > There was some discussion with Enric, but that didn't come to a conclusion, > I think. > Yes, my main concern is how this driver is instantiated, it is using one of the rdma nodes, see the rdma0 node vs rdma1, to instantiate the driver, mdp_rdma0: rdma@14001000 { compatible = "mediatek,mt8173-mdp-rdma"; "mediatek,mt8173-mdp"; reg = <0 0x14001000 0 0x1000>; clocks = <&mmsys CLK_MM_MDP_RDMA0>, <&mmsys CLK_MM_MUTEX_32K>; power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>; iommus = <&iommu M4U_PORT_MDP_RDMA0>; mediatek,larb = <&larb0>; mediatek,vpu = <&vpu>; }; mdp_rdma1: rdma@14002000 { compatible = "mediatek,mt8173-mdp-rdma"; reg = <0 0x14002000 0 0x1000>; clocks = <&mmsys CLK_MM_MDP_RDMA1>, <&mmsys CLK_MM_MUTEX_32K>; power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>; iommus = <&iommu M4U_PORT_MDP_RDMA1>; mediatek,larb = <&larb4>; }; My point is that DT is to describe hardware not a trick to instantiate drivers, so the "mediatek,mt8173-mdp" is completely unnecessary. We had the same issue with the MMSYS driver and the mediatek DRM driver, and we solved by having the mmsys driver instantiating the drm driver. I think we should apply the same solution here, see [1] for reference. If you want to continue the discussion maybe would be better Thanks, Enric [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/soc/mediatek/mtk-mmsys.c?id=667c769246b01c53ad0925d603d2a2531abd3ef2 > Regards, > > Hans > >> >> Changes in v2: >> - remove empty mtk_mdp_comp_init >> - update documentation for enum mtk_mdp_comp_type >> - remove comma after last element of mtk_mdp_comp_driver_dt_match >> >> Eizan Miyamoto (2): >> [media] mtk-mdp: add driver to probe mdp components >> [media] mtk-mdp: use pm_runtime in MDP component driver >> >> drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 172 ++++++++++++++--- >> drivers/media/platform/mtk-mdp/mtk_mdp_comp.h | 32 +-- >> drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 182 ++++++++++++------ >> drivers/media/platform/mtk-mdp/mtk_mdp_core.h | 1 + >> 4 files changed, 286 insertions(+), 101 deletions(-) >> >
