kernel: fix parsing fixed subpartitions

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit ed4641e9f1)

target/linux/generic/pending-5.4/410-mtd-parsers-ofpart-fix-parsing-subpartitions.patch

@@ -0,0 +1,76 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 6 May 2021 12:33:58 +0200
+Subject: [PATCH] mtd: parsers: ofpart: fix parsing subpartitions
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+ofpart was recently patched to not scan random partition nodes as
+subpartitions. That change unfortunately broke scanning valid
+subpartitions like:
+
+partitions {
+	compatible = "fixed-partitions";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	partition@0 {
+		compatible = "fixed-partitions";
+		label = "bootloader";
+		reg = <0x0 0x100000>;
+
+		partition@0 {
+			label = "config";
+			reg = <0x80000 0x80000>;
+		};
+	};
+};
+
+Fix that regression by adding 1 more code path. We actually need 3
+conditional blocks to support 3 possible cases. This change also makes
+code easier to understand & follow.
+
+Reported-by: David Bauer <mail@david-bauer.net>
+Fixes: 2d751203aacf ("mtd: parsers: ofpart: limit parsing of deprecated DT syntax
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/mtd/parsers/ofpart_core.c | 26 ++++++++++++++------------
+ 1 file changed, 14 insertions(+), 12 deletions(-)
+
+--- a/drivers/mtd/parsers/ofpart_core.c
++++ b/drivers/mtd/parsers/ofpart_core.c
+@@ -57,20 +57,22 @@ static int parse_fixed_partitions(struct
+ 	if (!mtd_node)
+ 		return 0;
+ 
+-	ofpart_node = of_get_child_by_name(mtd_node, "partitions");
+-	if (!ofpart_node && !mtd_is_partition(master)) {
+-		/*
+-		 * We might get here even when ofpart isn't used at all (e.g.,
+-		 * when using another parser), so don't be louder than
+-		 * KERN_DEBUG
+-		 */
+-		pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
+-			 master->name, mtd_node);
++	if (!mtd_is_partition(master)) { /* Master */
++		ofpart_node = of_get_child_by_name(mtd_node, "partitions");
++		if (!ofpart_node) {
++			/*
++			 * We might get here even when ofpart isn't used at all (e.g.,
++			 * when using another parser), so don't be louder than
++			 * KERN_DEBUG
++			 */
++			pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
++				master->name, mtd_node);
++			ofpart_node = mtd_node;
++			dedicated = false;
++		}
++	} else { /* Partition */
+ 		ofpart_node = mtd_node;
+-		dedicated = false;
+ 	}
+-	if (!ofpart_node)
+-		return 0;
+ 
+ 	of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
+ 	if (dedicated && !of_id) {

target/linux/kirkwood/patches-5.4/202-linksys-find-active-root.patch

@@ -22,7 +22,7 @@ Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
  	const char *partname;
  	struct device_node *pp;
  	int nr_parts, i, ret = 0;
-@@ -131,9 +134,15 @@ static int parse_fixed_partitions(struct
+@@ -133,9 +136,15 @@ static int parse_fixed_partitions(struct
  		parts[i].size = of_read_number(reg + a_cells, s_cells);
  		parts[i].of_node = pp;
  
@@ -41,7 +41,7 @@ Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
  		parts[i].name = partname;
  
  		if (of_get_property(pp, "read-only", &len))
-@@ -247,6 +256,18 @@ static int __init ofpart_parser_init(voi
+@@ -249,6 +258,18 @@ static int __init ofpart_parser_init(voi
  	return 0;
  }
  

target/linux/lantiq/patches-5.4/0101-find_active_root.patch

@@ -48,7 +48,7 @@
  
  	/* Pull of_node from the master device node */
  	mtd_node = mtd_get_of_node(master);
-@@ -93,7 +127,9 @@ static int parse_fixed_partitions(struct
+@@ -95,7 +129,9 @@ static int parse_fixed_partitions(struct
  		return 0;
  
  	parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
@@ -59,7 +59,7 @@
  		return -ENOMEM;
  
  	i = 0;
-@@ -142,6 +178,11 @@ static int parse_fixed_partitions(struct
+@@ -144,6 +180,11 @@ static int parse_fixed_partitions(struct
  		if (of_get_property(pp, "lock", &len))
  			parts[i].mask_flags |= MTD_POWERUP_LOCK;
  
@@ -71,7 +71,7 @@
  		i++;
  	}
  
-@@ -151,6 +192,11 @@ static int parse_fixed_partitions(struct
+@@ -153,6 +194,11 @@ static int parse_fixed_partitions(struct
  	if (quirks && quirks->post_parse)
  		quirks->post_parse(master, parts, nr_parts);
  
@@ -83,7 +83,7 @@
  	*pparts = parts;
  	return nr_parts;
  
-@@ -161,6 +207,7 @@ ofpart_fail:
+@@ -163,6 +209,7 @@ ofpart_fail:
  ofpart_none:
  	of_node_put(pp);
  	kfree(parts);

target/linux/mvebu/patches-5.4/400-find_active_root.patch

@@ -22,7 +22,7 @@ Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
  	struct device_node *pp;
  	int nr_parts, i, ret = 0;
  	bool dedicated = true;
-@@ -131,9 +134,13 @@ static int parse_fixed_partitions(struct
+@@ -133,9 +136,13 @@ static int parse_fixed_partitions(struct
  		parts[i].size = of_read_number(reg + a_cells, s_cells);
  		parts[i].of_node = pp;
  
@@ -39,7 +39,7 @@ Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
  		parts[i].name = partname;
  
  		if (of_get_property(pp, "read-only", &len))
-@@ -247,6 +254,18 @@ static int __init ofpart_parser_init(voi
+@@ -249,6 +256,18 @@ static int __init ofpart_parser_init(voi
  	return 0;
  }