linux-kernel - [PATCH 2/3] of: overlay: correctly apply overlay node with unit-address

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Date:   Fri,  7 Jul 2017 17:28:44 -0700
From:   frowand.list@...il.com
To:     Rob Herring <robh+dt@...nel.org>, pantelis.antoniou@...sulko.com,
        Pantelis Antoniou <panto@...oniou-consulting.com>
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] of: overlay: correctly apply overlay node with unit-address

From: Frank Rowand <frank.rowand@...y.com>

Correct existing node name detection when overlay node name has
a unit-address.

Expected test result is overlay will update the nodes and properties
for /testcase-data-2/fairway-1/ride@.../ after the patch is applied.

Before this patch is applied:

   Console error message near end of unittest:
      OF: Duplicate name in fairway-1, renamed to "ride@...#1"

   $ cd /proc/device-tree/testcase-data-2/fairway-1/
   $ # extra node: ride@...#1
   $ ls
   #address-cells  linux,phandle   phandle         ride@200
   #size-cells     name            ride@100        status
   compatible      orientation     ride@...#1
   $ cd /proc/device-tree/testcase-data-2/fairway-1/ride@.../
   $ ls track@...ncline_up
   ls: track@...ncline_up: No such file or directory
   $ ls track@...ncline_up
   ls: track@...ncline_up: No such file or directory

After this patch is applied:

   Console error message no longer occurs

   $ cd /proc/device-tree/testcase-data-2/fairway-1/
   $ # no extra node: ride@...#1
   $ ls
   #address-cells  compatible      name            phandle         ride@200
   #size-cells     linux,phandle   orientation     ride@100        status
   $ cd /proc/device-tree/testcase-data-2/fairway-1/ride@.../
   $ ls track@...ncline_up
   track@...ncline_up
   $ ls track@...ncline_up
   track@...ncline_up

Signed-off-by: Frank Rowand <frank.rowand@...y.com>
---
 drivers/of/overlay.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index c0e4ee1cd1ba..30aef51eeee5 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -118,6 +118,24 @@ static int of_overlay_apply_single_property(struct of_overlay *ov,
 	return of_changeset_update_property(&ov->cset, target, propn);
 }
 
+static struct device_node *child_by_full_name(const struct device_node *np,
+		const char *cname)
+{
+	struct device_node *child;
+	struct device_node *prev;
+
+	child = np->child;
+	while (child) {
+		of_node_get(child);
+		if (!of_node_cmp(cname, kbasename(child->full_name)))
+			break;
+		prev = child;
+		child = child->sibling;
+		of_node_put(prev);
+	}
+	return child;
+}
+
 static int of_overlay_apply_single_device_node(struct of_overlay *ov,
 		struct device_node *target, struct device_node *child)
 {
@@ -130,7 +148,7 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
 		return -ENOMEM;
 
 	/* NOTE: Multiple mods of created nodes not supported */
-	tchild = of_get_child_by_name(target, cname);
+	tchild = child_by_full_name(target, cname);
 	if (tchild != NULL) {
 		/* new overlay phandle value conflicts with existing value */
 		if (child->phandle)
-- 
Frank Rowand <frank.rowand@...y.com>