Hi Alan, On Thu, Feb 11, 2016 at 2:17 PM, atull <atull@xxxxxxxxxxxxxxxxxxxxx> wrote: >> > > I looked into it further and now I've got a solution for this issue >> > > that I can post soon. I can stop using the DT overlay configfs >> > > interface and add a sysfs file for applying an overlay to an FPGA >> > > region. The FPGA region implementation will see the overlay before it >> > > becomes part of the live tree. Then it can do the FPGA programming >> > > and see that succeed before the child nodes become part of the live >> > > tree. If FPGA programming fails, the overlay will be rejected before >> > > it becomes part of the live tree. By the time 'firmware-name' and the >> > > child nodes show up in the live tree, they will be post-configuration >> > > information. I agree this would be a very nice interface, but Rob is right, having two different interfaces to load device-trees is probably bad in general. >> Yes. If any handler returns error, the overlay doesn't go into the >> main tree. Handler type to be registed could be: >> >> int pre_add_handler(struct device_node *overlay, >> struct device_node *target) > > And a third parameter of some flags to indicate whether the > overlay is being added or removed. Looks good to me. >> That gives us the overlay after it's been unflattened and phandles >> resolved and the node that it was targeted to. I was going to >> need find_target_node() to be exported, but this avoids that. >> >> Registration could by compatible string, of match, or path. Path >> would be too rigid in my case, I'd want to register for compatible >> "fpga-region" Looks good to me. I think we're getting pretty close :) Moritz -- 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
