On 01/04/18 12:15, Kyle Evans wrote:
> On Thu, Jan 4, 2018 at 2:11 PM, Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>> On 12/31/17 22:59, kevans@xxxxxxxxxxx wrote:
>>> Currently, references cannot be made to nodes in the base that do not already
>>> have phandles, limiting us to nodes that have been referenced in the base fdt.
>>> Lift that restriction by allocating them on an as-needed basis.
>>
>> I am very confused. If I understand correctly, the problem is:
>>
>> A base devicetree contains a __symbols__ node, where one of the properties
>> in that node has a value which is a path to a node, where that node does
>> not have a phandle property.
>>
>> Is that correct?
>
> This is correct. Currently, the overlay support resolves the path to
> the node just fine, but then dies when it doesn't have a phandle. This
> changes it to allocate that phandle so that it and any further
> overlays can properly reference that node.
>
Then it appears that the base devicetree was not compiled with the
proper options. Using the .dts from patch 2/2, I can cause the problem
with:
$
dtc -O dts overlay_base_manual_symbols_auto_phandle.dts
/dts-v1/;
/ {
test: test-node {
test-int-property = <0x2a>;
test-str-property = "foo";
subtest: sub-test-node {
sub-test-property;
};
};
__symbols__ {
test = "/test-node";
};
};
But if I add the "-@" option, the phandle exists:
$ dtc -@ -O dts overlay_base_manual_symbols_auto_phandle.dts
WARNING: label test already exists in /__symbols__/dts-v1/;
/ {
test: test-node {
test-int-property = <0x2a>;
test-str-property = "foo";
phandle = <0x1>;
subtest: sub-test-node {
sub-test-property;
phandle = <0x2>;
};
};
__symbols__ {
test = "/test-node";
subtest = "/test-node/sub-test-node";
};
};
To go even further, there is no need to hand code a __symbols__
node with the current dtc:
$ cat overlay_base_manual_symbols_auto_phandle--no__symbols__.dts
/*
* Copyright (c) 2016 NextThing Co
* Copyright (c) 2016 Free Electrons
*
* SPDX-License-Identifier: GPL-2.0+
*/
/dts-v1/;
/ {
test: test-node {
test-int-property = <42>;
test-str-property = "foo";
subtest: sub-test-node {
sub-test-property;
};
};
};
$ dtc -@ -O dts overlay_base_manual_symbols_auto_phandle--no__symbols__.dts
/dts-v1/;
/ {
test: test-node {
test-int-property = <0x2a>;
test-str-property = "foo";
phandle = <0x1>;
subtest: sub-test-node {
sub-test-property;
phandle = <0x2>;
};
};
__symbols__ {
test = "/test-node";
subtest = "/test-node/sub-test-node";
};
};
Does this remove the need for the proposed patch, or am I still
missing something?
-Frank
--
To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
