Messages in this thread |  | | Date | Mon, 16 Dec 2013 11:34:12 -0700 | From | Stephen Warren <> | Subject | Re: [PATCHv7 03/12] iommu/of: check if dependee iommu is ready or not |
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On 12/12/2013 12:57 AM, Hiroshi Doyu wrote: > IOMMU devices on the bus need to be poplulated first, then iommu > master devices are done later. > > With CONFIG_OF_IOMMU, "iommus=" DT binding would be used to identify > whether a device can be an iommu msater or not. If a device can, we'll > defer to populate that device till an depending iommu device is > populated.
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> +int of_iommu_attach(struct device *dev) > +{ > + const __be32 *cur, *end; > + struct of_phandle_args args; > + > + of_property_for_each_phandle_with_args(dev->of_node, "iommus", > + "#iommu-cells", 0, args, cur, end) { > + if (!of_find_iommu_by_node(args.np)) > + return -EPROBE_DEFER;
I think that since of_find_iommu_by_node() should be calling iommu_get(iommu), the error-case here should loop over the IOMMUs that have successfully been acquired, and call iommu_put().
You'd also want to implement of_iommu_detach() or iommu_detach() to undo the iommu_get()s that happen within this function.
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