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Author SHA1 Message Date
Rob Herring
2347c96edc checks: add a check for duplicate unit-addresses of child nodes
Child nodes with the same unit-address (and different node names) are
either an error or just bad DT design. Typical errors are the unit-address
is just wrong (i.e. doesn't match reg value) or multiple children using the
same overlapping area. Overlapping regions are considered an error in new
bindings, but do exist in some existing trees. This check should flag
most but not all of those errors. Finding all cases would require doing
address translations and creating a full map of address spaces.

Mixing more than one address/number space at a level is bad design. It only
works if both spaces can use the same #address-cells and #size-cells sizes.
It also complicates parsing have a mixture of types of child nodes. The
best practice in this case is adding child container nodes for each
address/number space or using additional address bits/cells to encode
different address spaces.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-03-07 14:32:28 +11:00