Cannot hot remove a memory device

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

By following commit, I cannot hot remove a memory device.

ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes
commit e2ff39400d81233374e780b133496a2296643d7d

Details are follows:
When I add a memory device, acpi_memory_enable_device() always fails
as follows:

...
[ 1271.114116]  [ffffea121c400000-ffffea121c7fffff] PMD -> [ffff880813c00000-ffff880813ffffff] on node 3
[ 1271.128682]  [ffffea121c800000-ffffea121cbfffff] PMD -> [ffff880813800000-ffff880813bfffff] on node 3
[ 1271.143298]  [ffffea121cc00000-ffffea121cffffff] PMD -> [ffff880813000000-ffff8808133fffff] on node 3
[ 1271.157799]  [ffffea121d000000-ffffea121d3fffff] PMD -> [ffff880812c00000-ffff880812ffffff] on node 3
[ 1271.172341]  [ffffea121d400000-ffffea121d7fffff] PMD -> [ffff880812800000-ffff880812bfffff] on node 3
[ 1271.186872]  [ffffea121d800000-ffffea121dbfffff] PMD -> [ffff880812400000-ffff8808127fffff] on node 3
[ 1271.201481]  [ffffea121dc00000-ffffea121dffffff] PMD -> [ffff880812000000-ffff8808123fffff] on node 3
[ 1271.216041]  [ffffea121e000000-ffffea121e3fffff] PMD -> [ffff880811c00000-ffff880811ffffff] on node 3
[ 1271.230623]  [ffffea121e400000-ffffea121e7fffff] PMD -> [ffff880811800000-ffff880811bfffff] on node 3
[ 1271.245148]  [ffffea121e800000-ffffea121ebfffff] PMD -> [ffff880811400000-ffff8808117fffff] on node 3
[ 1271.259683]  [ffffea121ec00000-ffffea121effffff] PMD -> [ffff880811000000-ffff8808113fffff] on node 3
[ 1271.274194]  [ffffea121f000000-ffffea121f3fffff] PMD -> [ffff880810c00000-ffff880810ffffff] on node 3
[ 1271.288764]  [ffffea121f400000-ffffea121f7fffff] PMD -> [ffff880810800000-ffff880810bfffff] on node 3
...	
[ 1271.325841] acpi PNP0C80:03: acpi_memory_enable_device() error
...	

By this failure, hot added acpi_memory_info->enalbed is not set to 1.
So when hot removing the memory device, acpi_memory_remove_memory() does
nothing, since acpi_memory_info->enabled is 0. Thus I cannot hot remove
the memory device.

According to the messages, add_memory() succeeded. So I think that it is
caused by failing acpi_bind_memory_blocks().

I'm now investigating why acpi_bind_memory_blocks() fails.

Thanks,
Yasuaki Ishimatsu