From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> Extend the shared IOMMU code to skip over ->xlate() in case the IOMMU device pointed to by a slave device has been disabled in DT. Difficult to trigger in case a single IOMMU device is used, however when multiple IOMMUs are used and some of them are disabled in DT then this patch makes sure that ->xlate() only gets invoked for the enabled ones. Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> --- I used to keep this as a local check in the xlate() callback for the not-yet-merged-upstream R-Car Gen3 IPMMU driver stack. Since honoring DT disabled devices probably makes sense for most users it seems like a good plan to try to push it into the common subsystem level. Thanks to Geert for suggesting this ages ago. Developed on top of renesas-drivers-2017-01-24-v4.10-rc5 which includes a recent version of iommu/next. drivers/iommu/of_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- 0001/drivers/iommu/of_iommu.c +++ work/drivers/iommu/of_iommu.c 2017-01-27 13:19:22.540607110 +0900 @@ -159,7 +159,7 @@ const struct iommu_ops *of_iommu_configu np = iommu_spec.np; ops = of_iommu_get_ops(np); - if (!ops || !ops->of_xlate || + if (!ops || !ops->of_xlate || !of_device_is_available(np) || iommu_fwspec_init(dev, &np->fwnode, ops) || ops->of_xlate(dev, &iommu_spec)) goto err_put_node;
