On 10/31/2013 02:18 AM, Hiroshi Doyu wrote: > Stephen Warren <swarren@xxxxxxxxxxxxx> wrote @ Wed, 30 Oct 2013 23:44:04 +0100: > >>> + host1x { >>> + compatible = "nvidia,tegra30-host1x", "simple-bus"; >>> + nvidia,memory-clients = <&smmu TEGRA_SWGROUP_HC>; >>> + .... >>> + gr3d { >>> + compatible = "nvidia,tegra30-gr3d"; >>> + nvidia,memory-clients = <&smmu TEGRA_SWGROUP_NV >>> + TEGRA_SWGROUP_NV2>; >> >> Why one cell for the host1x property, and two cells for the gr3d >> property; shouldn't they be the same length? > > That can vary. Even a single device node in DT can belong to multiple > software groups. > >>> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c >> >>> +static u64 smmu_of_get_memory_client(struct device *dev) >> >>> + np = of_parse_phandle(dev->of_node, propname, 0); >>> + if (np != smmu_handle->dev->of_node) >>> + return ~0; >>> + >>> + prop = of_get_property(dev->of_node, propname, &bytes); >>> + if (!prop || !bytes) >>> + return ~0; >> >> of_parse_phandle_with_fixed_args() might be a good fit here, or perhaps >> require a property #smmu-cells in the SMMU node, thus allowing the >> non-fixed-length of_parse_phandle_with_args() to be used here. > > I once considered of_parse_phandle_with_args() but I couldn't use that > since "#smmu-cells" needed to be fixed in smmu node, not in client > node. In this case, the number of argument(number of swgroup IDs) > varies per client device. You could fix that by using a bitmask instead of a list. But, inverting the order of the properties to match the ARM SMMU binding might also solve this... -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html